JP5198325B2 - Web transport apparatus, web transport method, and web transport control program - Google Patents

Description

  The present invention relates to a web conveyance device, a web conveyance method, and a web conveyance control program.

  2. Description of the Related Art In recent years, a technology for transporting a web along a transport path composed of a plurality of rollers has been used in a product manufacturing line using a thin film-like flexible continuous material (hereinafter referred to as a web). And the technique which adjusts the tension | tensile_strength with respect to a web appropriately is also invented (for example, refer patent document 1).

However, when the conventional method achieves higher web conveyance speed, higher efficiency, and higher accuracy, it is difficult to prevent web damage by appropriately removing wrinkles generated during conveyance. ing. By the way, it has been found that wrinkles generated in the web are generally caused by so-called misalignment, in which the rollers that convey the web are not arranged in parallel. A web conveyance technology has been developed that can detect the occurrence of wrinkles that occur during web conveyance and prevent the occurrence of wrinkles (see, for example, Patent Document 2).

JP 2003-212406 A JP 2007-326657 A

  Now, the wrinkle generation prevention technique described in the cited document 2 by the present inventors can obtain a certain effect even in the present situation. It has also become clear that the generation of wrinkles cannot be sufficiently suppressed. The present invention has been made in view of such problems, and an object of the present invention is to prevent wrinkles from occurring on the web regardless of the transport conditions when performing web transport.

(Aspect of the Invention)
The following aspects of the present invention exemplify the configuration of the present invention, and will be described separately for easy understanding of various configurations of the present invention. Each item does not limit the technical scope of the present invention. Therefore, the technical aspects of the present invention also apply to those in which some of the constituent elements in each section are replaced, deleted, or other constituent elements are added while referring to the best mode for carrying out the invention. It can be included in the range.

(1) A web conveyance path constituted by a plurality of rollers including a driving roller and a free roller located upstream or downstream of the driving roller, and an imaging means for imaging the web conveyed along the web conveyance path And an alignment adjusting means for adjusting the angle of the shaft of the driving roller or the free roller, and a controller, the controller including driving information indicating a predetermined driving condition in the conveyance path, and the web A flying height calculating means for obtaining a flying height of the web in the drive roller or the free roller based on the physical property value;
Based on the calculation result of the flying height calculation means, an axis angle adjustment direction determination means for determining the adjustment direction of the angle of the shaft, and a straight line of a waveform generated on the web is detected from the captured image captured by the imaging means. And an image analysis means for analyzing the entry direction of the straight line with respect to the roller, and the shaft angle adjustment direction determination means determined according to the entry direction of the straight line with respect to the roller analyzed by the image analysis means . And a shaft angle control means for controlling the alignment adjusting means to drive the shaft in a direction (Claim 1).

The web conveyance device according to this section is configured to lift the web on the driving roller or the free roller based on the driving information indicating the predetermined driving condition in the conveyance path and the physical property value of the web by the shaft angle adjustment direction determination unit. The amount is determined, and the optimum adjustment direction of the shaft angle is determined based on the result. Moreover, the web conveyed on a web conveyance path is imaged by an imaging means. In addition, the image analysis means of the controller detects a straight line showing a waveform (waved phenomenon) like a wave generated on the web from the captured image, and analyzes the approach direction of the straight line with respect to the roller. This waveform is a precursor to the occurrence of wrinkles. And according to the approach direction of the straight line which shows a waveform, an alignment adjustment means is controlled and the axis | shaft of a drive roller or a free roller is driven to the direction defined by the shaft angle adjustment direction determination means.
As a result, so-called misalignment is corrected to a state in which a waveform that is a precursor of wrinkles is attenuated, and generation of wrinkles is avoided. The presence or absence of a waveform that is a precursor of wrinkles is constantly monitored by the image analysis means. When a straight line of the waveform is detected, the shaft is immediately driven in the direction determined by each of the means, and misalignment is performed. Corrections are made.

(2) In the shaft angle adjustment direction determining means of the above item (1), the driving is performed with respect to the straight line of the waveform generated on the web in accordance with the relationship between the flying height of the web and the combined surface roughness of the roller and the web. A web conveyance device in which an adjustment direction of the angle of the shaft is determined in a direction in which the shaft of the roller or the free roller becomes a right angle or an acute angle (Claim 2).
In the web conveyance device according to this section, in the shaft angle adjustment direction determining means, paying attention to the relationship between the flying height of the web and the combined surface roughness of the roller and the web, the shaft is moved in the optimum direction according to these relationships. An angle adjustment direction is determined. As a result, so-called misalignment is corrected to a state in which a waveform that is a precursor of wrinkles is attenuated, and generation of wrinkles is avoided.

(3) In the shaft angle adjustment direction determining means of the above item (2), when the relationship between the combined surface roughness σ of the driving roller and the web and the flying height h of the web with respect to the driving roller is h> σ, The direction of adjustment of the angle of the shaft is determined in a direction in which the axis of the driving roller is perpendicular to the straight line of the waveform generated on the web, and the combined surface roughness σ of the driving roller or the free roller and the web, When the relationship between the web flying height h with respect to the driving roller is h ≦ σ, the angle of the shaft in a direction in which the shaft of the driving roller or the free roller has an acute angle with respect to the straight line of the waveform generated on the web A web conveyance device in which the adjustment direction is determined (Claim 3).
In determining the direction of adjustment of the shaft angle of the driving roller or free roller, the web conveying device according to this section determines the magnitude of the combined surface roughness σ of the driving roller or free roller and the web and the flying height h of the web with respect to the roller. Focus on the relationship. When h> σ, that is, under the condition that the flying height of the web with respect to the roller is large and the frictional force between the roller and the web is small, the axis of the driving roller is perpendicular to the straight line of the waveform generated on the web. The direction of adjusting the angle of the shaft is determined in such a direction. On the other hand, when h ≦ σ, that is, under conditions where the web floating amount relative to the roller is small and the frictional force between the roller and the web is evenly generated in the entire contact area between the roller and the web, it occurs on the web. The adjustment direction of the shaft angle is determined so that the shaft of the driving roller or the free roller has an acute angle with respect to the waveform straight line.

(4) A web conveyance method using a web conveyance device including a web conveyance path constituted by a plurality of rollers including a drive roller and a free roller located upstream or downstream of the drive roller, A flying height calculation step for obtaining a flying height of the web on the driving roller or the free roller based on driving information indicating a predetermined driving condition and a physical property value of the web, and a calculation result of the flying height calculation step Based on the shaft angle adjustment direction determination step for determining the adjustment direction of the shaft angle of the drive roller or the free roller, and a picked-up image obtained by picking up the web conveyed along the conveyance path. It detects the linear waveform, an image analysis step of analyzing the approach direction with respect to the rollers of the straight line, the image analysis step Is Oite analysis, depending on the approach direction with respect to the roller of the linear, the axis angle adjusting direction determination in the direction determined in step, the web conveying method and a shaft angle control step of driving said shaft (claim 4 ).

The web conveyance method according to this section determines the flying height of the web on the drive roller or the free roller based on the drive information indicating the predetermined drive condition in the conveyance path and the physical property value of the web, and based on the result. Determine the optimal axis angle adjustment direction. In addition, the web conveyed on the web conveyance path is imaged, and a straight line having a waveform (waved phenomenon) that appears as a wave generated on the web is detected from the captured image, and the approach direction of the straight line with respect to the roller is detected. Is analyzed. This waveform is a precursor to the occurrence of wrinkles.
And according to the approach direction of the straight line which shows a waveform, the axis | shaft of a drive roller or a free roller is driven in the defined direction.
As a result, so-called misalignment is corrected to a state in which a waveform that is a precursor of wrinkles is attenuated, and generation of wrinkles is avoided. In addition, the occurrence of a waveform that is a precursor of wrinkles is constantly monitored, and if a straight line of the waveform is detected, the axis is immediately driven in the direction determined by the above procedure to perform misalignment correction. .

(5) In the shaft angle adjustment direction determination step of the above item (4), the drive is performed with respect to the waveform straight line generated on the web in accordance with the relationship between the flying height of the web and the combined surface roughness of the roller and the web. A web conveyance method in which an adjustment direction of the angle of the shaft is determined in a direction in which the shaft of the roller or the free roller becomes a right angle or an acute angle (Claim 5).
In the web conveyance method according to this section, in the shaft angle adjustment direction determination step, pay attention to the relationship between the flying height of the web and the combined surface roughness of the roller and the web, and in the optimum direction according to these relationships, Determine the angle adjustment direction. As a result, so-called misalignment is corrected to a state in which a waveform that is a precursor of wrinkles is attenuated, and generation of wrinkles is avoided.

(6) In the shaft angle adjustment direction determination step of the above item (5), when the relationship between the combined surface roughness σ of the driving roller and the web and the flying height h of the web with respect to the driving roller is h> σ, The direction of adjustment of the angle of the shaft is determined in a direction in which the axis of the driving roller is perpendicular to the straight line of the waveform generated on the web, and the combined surface roughness σ of the driving roller or the free roller and the web, When the relationship between the web flying height h with respect to the driving roller is h ≦ σ, the angle of the shaft in a direction in which the shaft of the driving roller or the free roller has an acute angle with respect to the straight line of the waveform generated on the web The web conveyance device in which the adjustment direction is determined (Claim 6).
The web conveying method according to this section determines the magnitude of the combined surface roughness σ of the driving roller or free roller and web and the flying height h of the web with respect to the roller in determining the adjustment direction of the shaft angle of the driving roller or free roller. Focus on the relationship. When h> σ, that is, under the condition that the flying height of the web with respect to the roller is large and the frictional force between the roller and the web is small, the axis of the driving roller is perpendicular to the straight line of the waveform generated on the web. The direction of adjusting the angle of the shaft is determined in the direction of On the other hand, when h ≦ σ, that is, under conditions where the web floating amount relative to the roller is small and the frictional force between the roller and the web is evenly generated in the entire contact area between the roller and the web, it occurs on the web. An adjustment direction of the shaft angle is determined in a direction in which the shaft of the driving roller or the free roller becomes an acute angle with respect to the waveform straight line.

(7) Alignment adjusting means for adjusting the angle of the shaft of the driving roller or the free roller, and a web conveyance path constituted by a plurality of rollers including a driving roller and a free roller located upstream or downstream of the driving roller. the controller of the web transport apparatus provided with bets, and driving information indicating a predetermined drive conditions of the transport path, on the basis on the physical properties of the web, obtaining the flying height of the web in said drive roller or said free roller From the flying height calculation means, the shaft angle adjustment direction determination means for determining the adjustment direction of the angle of the shaft based on the calculation result of the flying height calculation means, and the captured image obtained by imaging the web conveyed along the conveyance path An image analysis means for detecting a straight line of a waveform generated on the web and analyzing an approach direction of the straight line with respect to the roller Were analyzed by the image analysis means, according to the approach direction with respect to the roller of the straight line, the axis to be the direction determined by the axis angle adjusting direction determination means, for controlling the alignment adjusting means to drive said shaft A web conveyance control program including a control logic that functions as an angle control means.

The web conveyance control program according to the present section is a flying height calculation unit that obtains the flying height of the web on the driving roller or the free roller based on driving information indicating predetermined driving conditions in the conveyance path and the physical property value of the web. Function as. Furthermore, an optimum adjustment direction of the shaft angle is determined based on the calculation result of the flying height calculation means. In addition, the controller of the web conveyance device images the web conveyed on the web conveyance path, and detects a straight line indicating a waveform (waved phenomenon) such as a wave generated on the web from the captured image, It functions as an image analysis means for analyzing the approach direction of the straight roller. This waveform is a precursor to the occurrence of wrinkles.
Then, it functions as a shaft angle adjustment direction determination means for controlling the alignment adjustment means in accordance with the approach direction of the straight line indicating the waveform to drive the shaft of the drive roller or the free roller in an appropriate direction.
Then, by functioning as a shaft angle control unit that drives the shaft of the drive roller or the free roller in the direction determined by the shaft angle adjustment direction determination unit, so-called misalignment attenuates a waveform that is a precursor of wrinkles. The state is corrected to avoid the occurrence of wrinkles. The presence or absence of a waveform that is a precursor of wrinkles is constantly monitored by the image analysis means. When a straight line of the waveform is detected, the shaft is immediately driven in the direction determined by each of the means, and misalignment is performed. Corrections are made.

(8) In the shaft angle adjustment direction determination means according to the above (7), the drive is performed with respect to a straight line of a waveform generated on the web in accordance with the relationship between the flying height of the web and the combined surface roughness of the roller and the web. A web conveyance control program in which an adjustment direction of the angle of the shaft is determined in a direction in which the shaft of the roller or the free roller becomes a right angle or an acute angle (Claim 8).
The web conveyance control program according to this section focuses on the relationship between the flying height of the web and the combined surface roughness of the roller and the web in the shaft angle adjustment direction determination means, and the shaft is adjusted in the optimum direction according to these relationships. The angle adjustment direction is determined. As a result, so-called misalignment is corrected to a state in which a waveform that is a precursor of wrinkles is attenuated, and generation of wrinkles is avoided.

(9) In the shaft angle adjustment direction determination means of (8) above, when the relationship between the combined surface roughness σ of the driving roller and the web and the flying height h of the web with respect to the driving roller is h> σ, The direction of adjustment of the angle of the shaft is determined in a direction in which the axis of the driving roller is perpendicular to the straight line of the waveform generated on the web, and the combined surface roughness σ of the driving roller or the free roller and the web, When the relationship between the web flying height h with respect to the driving roller is h ≦ σ, the angle of the shaft in a direction in which the shaft of the driving roller or the free roller has an acute angle with respect to the straight line of the waveform generated on the web A web conveyance control program in which the adjustment direction is determined (claim 9).
The web conveyance control program according to this section determines the adjustment direction of the shaft angle of the driving roller or the free roller, the combined surface roughness σ of the driving roller or the free roller and the web, and the flying height h of the web with respect to the roller. It focuses on the magnitude relationship. When h> σ, that is, under the condition that the flying height of the web with respect to the roller is large and the frictional force between the roller and the web is small, the axis of the driving roller is perpendicular to the straight line of the waveform generated on the web. The direction of adjusting the angle of the shaft is determined in such a direction. On the other hand, when h ≦ σ, that is, under conditions where the web floating amount relative to the roller is small and the frictional force between the roller and the web is evenly generated in the entire contact area between the roller and the web, it occurs on the web. The adjustment direction of the shaft angle is determined so that the shaft of the driving roller or the free roller has an acute angle with respect to the waveform straight line.

  Since this invention was comprised in this way, when performing web conveyance, it can prevent appropriately that wrinkles generate | occur | produce on a web irrespective of conveyance conditions.

It is explanatory drawing for demonstrating the mechanism which wrinkles generate | occur | produce in a web, (a) is the perspective view which showed the relationship between two rollers and a web, (b) is the side view, (c) is the top view. is there. It is a graph which shows the conditions for preventing generation | occurrence | production of a wrinkle and carrying out stable conveyance of a web. It is a side view which shows typically the web conveyance apparatus which concerns on embodiment of this invention. It is a top view of the web conveyance apparatus shown by FIG. It is a block diagram which shows the structure of the controller of the web conveyance apparatus which concerns on embodiment of this invention. It is a flowchart which shows the operation | movement procedure of the web conveyance apparatus which concerns on embodiment of this invention. In the web conveyance device concerning an embodiment of the invention, it is an explanatory view showing the control method of a guide roller when the waveform (rippling phenomenon) which becomes a precursor of a wrinkle occurs on the web, (a) is a web In the case where the shaft angle is adjusted in the direction in which the axis of the driving roller is perpendicular to the waveform straight line generated on the top, (b) is the axis of the driving roller with respect to the waveform straight line generated on the web. This shows a case where the angle of the shaft is adjusted in a direction in which becomes an acute angle.

Embodiments of the present invention will be described below with reference to the drawings. Here, first, after explaining the outline of the mechanism of the generation of the wrinkle of the web clarified by the inventor of the present application, the configuration and operation of the web conveyance device that conveys the web while preventing the generation of the wrinkle will be sequentially described. Do.
In addition, the description of the said patent document 2 is suitably quoted and demonstrated about the structure part partially overlapped with the invention of the said patent document 2 by the present inventors.

[Wrinkle generation mechanism during web conveyance]
Initially, with reference to FIG. 1, the mechanism which a wrinkle generate | occur | produces on a web during web conveyance is demonstrated. FIG. 1 is an explanatory view for explaining the mechanism of wrinkle generation, wherein (a) is a perspective view showing the relationship between two rollers and a web, (b) is a side view thereof, and (c) is a side view thereof. A top view is shown. FIG. 1 shows a state where the web 10 is conveyed on two rollers 2 (2 ₁ , 2 ₂ ). Here are those web 10 from the roller 2 ₁ upstream the roller 2 ₂ downstream direction (shown transparent in the figure) is being conveyed, the roller 2 ₁ upstream passively free roller rotating, the roller 2 ₂ on the downstream side is a driving roller comprising a power source.

(Wrinkle generation condition)
First, conditions for generating wrinkles on the web 10 during the conveyance of the web 10 will be described.
Normally, when the rollers 2 ₁ and 2 ₂ are arranged in parallel, the web 10 does not wrinkle. However, for example, rollers _{2 2,} distortion (skew) occurs for roller _{2 1,} if the misalignment between the roller _{2 1} and the roller _{2 2} is generated, the web 10 is roller _{2 2} on the tangent receive a shear force S _F in due to the bending moment. Here, the web 10, given a very thin beam of the roller 2 ₁ upstream fixed end, the web 10 is subjected to shear force S _F, when you Tawamo in the plane. If shear stress at this time if greater than the critical buckling stress when regarded web 10 a plate, buckling B _L in a central position of the web 10 just before entering the roller 2 ₂ skew occurs begins to occur This is the starting point for wrinkles.
That is, the roller 2 ₂ of the skew angle theta is the following (1) wrinkle occurs when a critical misalignment angle theta _cr more in the expression.

Here, a is the span [m] between the rollers, L is the web width [m], E _x is the Young's modulus [Pa] of the web in the web conveyance direction, and σ _x is the tensile stress [Pa] in the web conveyance direction due to tension. , Σ _zcr represents the critical buckling stress [Pa], respectively.
The tensile stress σ _x is given by the following equation (2).

Here, T is show web tension [N / m], _{t f} is the web thickness [m], respectively.
The critical buckling stress σ _zcr is given by the following equation (3).

However, σ _e , ζ ₁ and ζ ₂ are given by the following equation (4).
In addition, the integer i in the expression (3) is an arbitrary integer that satisfies the following expression (5).

(Wrinkle propagation condition)
Next, a condition in which wrinkles generated on the web 10 propagate along the conveyance direction of the web 10 will be described.
Usually, when the web 10 wrinkles occurs passes through the roller 2 _2, the critical buckling stress of the web 10 wound along the roller 2 _2, since the much larger than the critical buckling stress of the plate of the sufficient frictional force F _F for supporting a large shearing force between the web 10 and the roller 2 _2, if does not act, the web 10 on the roller 2 ₂ is not buckling, wrinkles disappear To do.
However, the web 10 is also on the roller 2 ₂ in the case of acting sufficient frictional force F _F between the web 10 and the roller 2 ₂ is kept buckled, wrinkles propagates.
That is, wrinkles propagate when the tension on the web 10 is equal to or higher than the critical upper limit tension T _wick shown in the following formula (6).

Here, t _f is the web thickness [m], μ is the coefficient of friction between the web and the roller, L is the web width [m], E _x is the Young's modulus [Pa] of the web in the web conveyance direction, and E _z is the web width. The Young's modulus [Pa] of the web in the direction, v _x represents the Poisson ratio of the web in the web conveyance direction, and v _z represents the Poisson ratio of the web in the web width direction.
The friction coefficient μ is given by the following equation (7).

Here, R is a roller radius [m], and B is a web winding angle [rad]. Further, mu _l is given by the following equation (8).

Here, mu _c web - boundary friction coefficient between the roller, h is an air film thickness, i.e., the flying height of the web 10 against the roller 2 ₂ [m], sigma web - Synthesis surface roughness between rollers [m] Respectively.
However, the surface roughness σ is a composite value of the roller surface roughness σ _r and the web surface roughness σ _w as shown in the following equation (9).

  The air film thickness h is given by the following equation (10).

Here, η is the air film viscosity (or the viscosity of the fluid when the surrounding is a fluid other than air) [Pa · s], T is the web tension [N / m], and k is the air permeability of the web [m. ² ] and x are web conveyance direction coordinates [m], and U is web conveyance speed [m / s]. The web conveyance direction coordinate x is x = −RB / 2 at the entrance of the winding angle and x = RB / 2 (−RB / 2 ≦ x ≦ RB / 2) at the exit. The web conveyance speed U is an addition value (U _r + U _w ) of the roller speed U _r and the web speed U _w .
Thus, if the tension T with respect to the web 10 is less than the critical upper limit tension T _wick shown in the above equation (6), wrinkles will not occur. However, if the tension T is too small, the frictional force between the web 10 and the roller 2 is reduced, slipping is likely to occur, and the web 10 is difficult to convey.
Therefore, here, the critical tension (critical lower limit tension) T _slip of the tension T at which _slip does not occur is obtained.
In general, slip occurs when μ = 0, which is when h = 3σ from equation (8).

  That is, the right side of the lower expression (11) is 3σ.

Therefore, the critical lower limit tension T _slip can be obtained by the following equation (12).

The above conditions will be described with reference to FIG. The upper diagram of FIG. 2 is a graph showing conditions for preventing wrinkles and stably conveying the web, where the horizontal axis is the tension T against the web, and the vertical axis is the skew angle of the roller (misalignment angle). ) M as θ. In the middle diagram of FIG. 2, the horizontal axis represents the tension T, and the vertical axis represents the web flying height h with respect to the roller. Further, in the lower diagram of FIG. 2, the horizontal axis represents the tension T, and the vertical axis represents the web-roller friction coefficient μ.
As shown in the upper diagram of FIG. 2, the tension T is larger than the critical lower limit tension T _slip calculated by the equation (12) and smaller than the critical upper limit tension T _wick calculated by the equation (6). In this case, the web 10 can be stably conveyed without generation of wrinkles or slip.
Note that slip occurs when the tension T becomes smaller than the critical lower limit tension T _slip , and wrinkles occur when the tension T becomes larger than the critical upper limit tension T _wick . However, even in this case, the skew angle theta of the rollers 2 _2, wherein (1) is made smaller than the critical misalignment angle theta _cr calculated by the equation, the web 10 stably without generating wrinkles Can be transported.

Thus, in the web transport, in order to convey the web stably is without generating wrinkles or slip, the skew angle of the tension T and the roller 2 ₂ of the web 10 theta is, in the graph of FIG. 2, slip that turning generation region S _L creases generation region W _R, it is necessary to always hold the state to enter the stable area S _T.

In addition, in the embodiment of the present invention, the frictional force _{F F} acting between the web 10 and the roller _{2 2,} and the roller _{2 2} and the web 10, the flying height h of the web 10 against the roller _{2 2} [m] It is influenced by the magnitude relationship with. (Note that a composite value of the surface roughness sigma _w synthetic surface roughness sigma [m] roller 2 ₂ surface roughness sigma _r and the web 10. (9) See.)

According to studies by the present inventors, when h ≦ sigma, i.e. synthesis of the flying height h is, the driving roller 2 ₂ or a free roller 2 ₁ and the web 10 of the web 10 relative to the drive roller 2 ₂ or a free roller 2 ₁ when: the surface roughness sigma, the friction force F _F acting on the web 10 between the driving roller 2 ₂ or roller 2 ₂ is made uniform in the contact area throughout the time of h> sigma, that is, the driving roller 2 ₂ for the flying height h of the web 10, when the synthetic surface exceeds roughness σ of the roller 2 ₂ and the web 10, when misalignment occurs, the frictional force F _F acting between the web 10 and the roller 2 _2, the contact It has been confirmed that non-uniformity occurs throughout the region. That is, with the flying height h = σ shown in the middle diagram of FIG. 2 as the boundary, as shown in the lower diagram of FIG. 2, in the region of h ≦ σ, the average value T _AV of the tension T is used as a reference. even if a portion T _H and a low portion T _L higher tension than the value, the web - although the friction coefficient between the roller μ constant, in the region of h> sigma, mainly the mean T _AV tension When it uneven it from lower value T _L and a high value T _H, mu also becomes uneven. As shown in the lower diagram of FIG. 3, in the region where the flying height h> 3σ, μ = 0 is constant.

Accordingly, embodiments of the present invention, the misalignment for eliminating, in determining the correction direction of the roller 2 axis, and σ driving roller 2 ₂ or a free roller 2 ₁ and the web of synthetic surface roughness, the rollers The size relationship between the web 10 and the flying height h of the web 10 with respect to 2 is noted.
Hereinafter, the tension T and the skew angle of the roller θ of the web 10, the configuration and operation of the web transport apparatus that can be operated in a stable area S _T is described.

[Configuration of web transport device]
First, with reference to FIG.3 and FIG.4, the structure of the web conveyance apparatus which concerns on this invention is demonstrated. FIG. 3 is a side view showing a schematic configuration of the web conveyance device according to the present invention. FIG. 4 is a plan view of the web conveyance device according to the present invention.
As shown in FIG. 3 and FIG. 4, the web conveying device 1 includes a plurality of rollers on a web 10, which is a flexible continuous material such as continuous paper, plastic film, and metal film, without causing wrinkles or slipping. 2 is conveyed.
Here, the web conveyance device 1 is configured to convey the web 10 from the feeding unit 100 to the winding unit 101. Further, here, the web conveying device 1 includes a plurality of rollers 2, a camera 3, a tension adjusting unit 4, an alignment adjusting unit 5, a roller driving unit 6, and a controller 7.

  The roller 2 is configured to convey the web 10 from upstream to downstream by rotating about a shaft. Here, the roller 2 includes an auxiliary roller 2a, a dancer roller 2b, a guide roller 2c, and a drive roller 2d. In addition, these rollers 2 are installed so that each axis | shaft may become parallel. However, since the parallelism of each axis is not absolute, the parallelism is maintained by controlling the skew angle of the guide roller 2c or the drive roller 2d described later.

  The auxiliary roller 2a is an auxiliary free roller that conveys the web 10 without both ends of the shaft 20a being fixed to the main body of the web conveying device 1 and having a driving force. Here, the auxiliary roller 2a plays a role of guiding the web 10 delivered from the delivery unit 100 to the dancer roller 2b.

  The dancer roller 2b is a free roller capable of adjusting the position of the shaft 20b, and generates tension on the web 10. Here, the dancer roller 2b generates tension on the web 10 by driving the shaft 20b in a direction perpendicular to the installation surface by a tension adjusting means 4 described later.

  The guide roller 2c is a free roller in which one end of the shaft 20c is fixed to the main body of the web conveyance device 1 and the position of the other end (moving end) can be adjusted. Here, the guide roller 2c plays the role of maintaining the parallelism of the shaft with the upstream roller by adjusting the position of the other end in the horizontal direction with respect to the installation surface by the alignment adjusting means 5 described later. .

  The driving roller 2d rotates when the shaft 20d is rotationally driven by roller driving means 6 described later, and conveys the web 10 by frictional force with the web 10. The drive roller 2c is also a roller in which one end of the shaft 20d is fixed to the main body of the web conveyance device 1 and the position of the other end (moving end) can be adjusted. Here, the driving roller 2 d sends the web 10 sent from the guide roller 2 c to the winding unit 101.

  The camera (imaging means) 3 is provided in the vicinity of the guide roller 2c and the driving roller 2d (that is, the roller provided with the alignment adjusting means 5), and the web 10 conveyed on the guide roller 2c and the driving roller 2d is detected. The image is taken. The images picked up by the camera 3 are sequentially output to the controller 7 described later in units of frames as video signals. The image picked up by the camera 3 is analyzed in the controller 7 and it is determined whether or not the web 10 has a waveform that is a precursor to the occurrence of wrinkles. The analysis method will be described in the description of the configuration of the controller 7 to be described later.

The tension adjusting means 4 adjusts the tension of the web 10 by adjusting the position of the shaft 20b of the dancer roller 2b. Here, the tension adjusting means 4 moves the position of the shaft 20b of the dancer roller 2b in the vertical direction with respect to the installation surface based on the drive signal (tension adjustment drive signal) from the controller 7, thereby Adjust the tension. The tension adjusting means 4 can be constituted by, for example, a hydraulic cylinder, a pneumatic cylinder, or the like.
Here, the tension adjusting means 4 adjusts the axis 20b of the dancer roller 2b in the vertical direction, but this direction is not limited to this, and it depends on the arrangement of the upstream and downstream rollers, etc. Any direction that can adjust the tension on the web 10 may be used.
Further, here, the tension adjusting means 4 includes a tension sensor 40 inside, measures the tension with respect to the web 10 by the tension sensor 40, and outputs the tension to the controller 7.

The alignment adjusting means 5 adjusts the skew angle (misalignment angle) of the shafts 20c and 20d of the guide roller 2c and the drive roller 2d. Here, the alignment adjusting means 5 determines the position of the moving end of the shaft 20c of the guide roller 2c and the shaft 20d of the driving roller 2d with respect to the installation surface based on the driving signal (alignment adjusting driving signal) from the controller 7. By operating in the horizontal direction, the skew angle of the shaft 20c and the driving roller 2d is adjusted. The alignment adjusting means 5 may adjust the position of the moving end of the shaft 20c and the driving roller 2d with, for example, a micro screw, or deform the piezo element with voltage, magnetism, or the like to change the shaft 20c and the driving roller 2d. The position of the moving end may be adjusted.
Here, the alignment adjusting means 5 adjusts the shaft 20c of the guide roller 2c and the shaft 20d of the drive roller 2d in the horizontal direction, but this direction is not limited to the horizontal direction. Any direction that can adjust the input direction of the web 10 to the guide roller 2c may be used.

  The roller driving means 6 rotates the shaft 20d of the driving roller 2d and is, for example, a general motor. Here, the roller driving means 6 rotates the shaft 20d of the driving roller 2d based on a driving signal (power frequency signal) from the controller 7.

  The controller 7 is a control device that controls the entire web conveyance device 1 and is realized by a calculation means such as a general computer including a CPU (Central Processing Unit), a RAM (Random Access Memory), and the like.

Here, the functional configuration of the controller 7 will be described with reference to FIG. 5 (refer to FIGS. 3 and 4 as appropriate). FIG. 5 is a functional block diagram showing the configuration of the controller.
Here, the controller 7 includes storage means 70, critical tension calculation means 71, tension control means 72, image analysis means 73, shaft angle control means 74, drive control means 75, and shaft angle adjustment direction determination means. 76.

The storage means 70 stores physical property values, drive information, and the like of the web 10 and is a general storage device such as a semiconductor memory or a hard disk.
The physical property values of the web 10 stored in the storage means 70 include Young's modulus, Poisson's ratio, web thickness, web width, web surface roughness, friction coefficient, and the like described in the equations (1) to (12). It is a unique value.

The drive information stored in the storage means 70 includes the roller type (drive roller or free roller), roller surface roughness, roller radius, web winding angle, web conveyance speed, air film viscosity, etc. (1) to (1) It is a value which shows the conditions at the time of operating the web conveyance apparatus 1 demonstrated in Formula 12).
Note that these physical property values and driving information may be stored in the storage unit 70 in advance, or may be input from the outside via an input unit such as a keyboard (not shown).
Further, the storage unit 70 stores a critical value calculated by a critical tension calculation unit 71 described later.

  The critical tension calculating means 71 calculates, as a critical condition, a condition that does not generate wrinkles or slips on the web 10 when the web 10 is conveyed. Here, the critical tension calculating means 71 includes a critical upper limit tension calculating means 71a and a critical lower limit tension calculating means 71b.

The critical upper limit tension calculating means 71a calculates the upper limit value of the tension applied to the web 10 when wrinkles occur in the web 10. Here, the critical upper limit tension calculating means 71a calculates the critical upper limit tension T _wick described in the equation (6) based on the physical property value and driving information of the web 10 stored in the storage means 70. This critical upper limit tension T _wick is output to the tension control means 72.

The critical lower limit tension calculating means 71b calculates a lower limit value of the tension applied to the web 10 when the web 10 slips. Here, the critical lower limit tension calculating means 71b calculates the critical lower limit tension T _slip described in the above equation (12) based on the physical property values and driving information of the web 10 stored in the storage means 70. This critical lower limit tension T _slip is output to the tension control means 72.

  The tension control means 72 controls the tension on the web 10. Here, the tension control means 72 controls the tension with respect to the web 10 by adjusting the position of the shaft 20b of the dancer roller 2b. Here, the tension control means 72 includes an initial value setting means 72a, a measured tension input means 72b, and a tension range control means 72c.

The initial value setting means 72 a is for setting an initial value of tension for the web 10. Here, the initial value setting unit 72a, based on the critical upper limit tension _{T wik} and critical lower tension _{T slip} calculated by the critical tension calculating means 71, the initial value of tension _{T O} satisfying the following equation (13) And For example, the average value of the critical upper limit tension T _wick and the critical lower limit tension T _slip is defined as the tension T _O.

  The measured tension input means 72b is for inputting the tension of the web 10 measured by the tension sensor 40 of the tension adjusting means 4 as a measured value. The measured tension value input by the measured tension input means 72b is output to the tension range control means 72c.

The tension range control means 72c controls the dancer roller 2b so that the tension of the web 10 falls within the range of the critical upper limit tension T _wick and the critical lower limit tension T _slip .
Here, the tension range control means 72c outputs a drive signal (tension adjustment drive signal) to the tension adjustment means 4 so that the initial value set by the initial value setting means 72a becomes the tension for the web 10. . The tension range control unit 72c is configured so that the tension range input by the measurement tension input unit 72b is successively within the range of the critical upper limit tension T _wick and the critical lower limit tension T _slip during the conveyance of the web 10. A drive signal (tension adjustment drive signal) is output to the tension adjusting means 4.

  The image analysis means 73 detects a waveform generated on the web 10 from the image based on the color or brightness of the image captured by the camera 3, and determines the direction of the straight line based on a predetermined coordinate system. This is analyzed as the approach direction of the corrugated guide roller 2c or drive roller 2d. Here, the image analysis means 73 includes an image input means 73a and a waveform detection means 73b.

  The image input means 73a is for inputting an image captured by the camera 3. This image input means 73a inputs the frame unit image captured by the camera 3 in time series and outputs it to the waveform detection means 73b.

  The waveform detection unit 73b analyzes the image input from the image input unit 73a, thereby determining the waveform that is a precursor to the occurrence of wrinkles in the web 10 and the approach direction of the waveform to the guide roller 2c or the drive roller 2d. It is to detect.

When the web 10 is wrinkled, a waveform as a precursor is generated on the web 10 in advance. Therefore, the waveform detection unit 73b detects the waveform (see FIG. 7) by analyzing the image captured by the camera 3.
For example, the waveform detection unit 73b detects a straight line (a straight line of a waveform that is a precursor to the occurrence of wrinkles) from the image by using a Hough transform technique that is a known technique, and the direction of the straight line (entrance of the waveform) Direction).

The waveform generated on the web 10 can be detected as a straight line by detecting pixel values belonging to a predetermined color vector when the image is a color image. In the case of a black and white image, the waveform can be detected as a straight line based on the difference in luminance.
Further, the waveform detecting means 73b can obtain the slope of the straight line by converting the straight line pixel from the xy coordinate system to the ρ-θ coordinate system by Hough transform.
The fact that the waveform is detected by the waveform detection means 73b and the approach direction of the waveform to the guide roller 2c are output to the shaft angle control means 74.

  The shaft angle control means 74 controls the skew angle of the guide roller 2c based on the approach direction of the waveform detected by the waveform detection means 73b. Here, the shaft angle control means 74 sends a drive signal (alignment adjustment) to the alignment adjustment means 5 in a direction in which the angle formed by the waveform approaching direction to the guide roller 2c and the axial direction of the guide roller 2c is perpendicular. Drive signal).

The drive control means 75 drives the drive roller 2d by outputting a drive signal (power frequency signal) instructing a predetermined speed to the roller drive means 6 for conveying the web 10. Here, the drive control means 75 outputs a drive signal (power frequency signal) based on the web conveyance speed stored in the storage means 70.
The controller 7 can be operated by a web conveyance control program that causes a computer to function as each of the means described above.

  The shaft angle adjustment direction determination means 76 is based on the drive information indicating the predetermined drive condition in the conveyance path and the physical property value of the web 10, both of which are stored in the storage means 70, and the free roller 2 c or the drive roller. The flying height h of the web 10 in 2d is obtained, and the adjustment direction of the shaft angle is determined based on the result. The flying height calculation means 76a and the shaft angle adjustment direction determination means 76b are provided.

The flying height calculation unit 76a calculates the flying height h of the web 10 with respect to the roller 2 described in the equation (15). This flying height h is output to the shaft angle adjustment direction determination means 76b.
Then, in the shaft angle adjustment direction determination means 76b, it is detected by the image analysis means from the magnitude of the combined surface roughness σ of the free roller 2c or the drive roller 2d and the web 10 and the flying height h of the web 10 with respect to these rollers 2. The direction of adjustment of the angle of the shafts 20c and 20d of the free roller 2c or the drive roller 2d with respect to the straight line of the waveform generated on the web 10 is determined, and information on the direction is output to the shaft angle control means 74.

[Operation of web transport device]
Next, referring to FIG. 6 (refer to FIGS. 3, 4 and 5 as appropriate), the operation of the web conveyance device 1 will be described. FIG. 6 is a flowchart showing the operation of the web conveyance device according to the present invention. Here, the operation of the web conveyance device 1 will be described focusing on the operation of the controller 7.

(Critical tension calculation step)
First, the web conveyance device 1 calculates the upper limit value (critical upper limit tension T _wik ) of the web 10 when wrinkles occur in the web 10 by the critical upper limit tension calculation means 71a of the critical tension calculation means 71 (step S1). ). Furthermore, the web conveyance device 1 calculates the lower limit value (critical lower limit tension T _slip ) of the web 10 when the web 10 slips by the critical lower limit tension calculation means 71b of the critical tension calculation means 71 (step). S2).

Then, the web conveyance device 1 sets an initial value (tension T _O ) of the tension with respect to the web 10 within the range of the critical upper limit tension T _wick and the critical lower limit tension T _slip by the initial value setting means 72 a of the tension control means 72. (Step S3).
Moreover, the web conveyance apparatus 1 controls the dancer roller 2b by the tension range control means 72c of the tension control means 72 so that the tension with respect to the web 10 becomes the tension set in step S3 (step S4).
Through the above operation, the web transport apparatus 1 has been initially set for tension.

Thereafter, the web conveyance device 1 outputs a drive signal from the drive control means 75 to the roller drive means 6 to rotate the drive roller 2d and convey the web 10 (step S5). Then, the web conveyance device 1 executes the following tension control step, image analysis step, and shaft angle control step.
Here, when the end of the operation is instructed (Yes in step S6), the web conveyance device 1 ends the operation. On the other hand, when the end of the operation is not instructed (No in step S6), the process proceeds to step S7.

(Tension control step)
First, the web conveyance device 1 inputs the tension T of the web 10 measured by the tension sensor 40 of the tension adjusting means 4 by the measured tension input means 72b of the tension control means 72 during conveyance of the web 10 (step S7). .
Then, the web conveyance device 1 causes the tension range control unit 72c so that the tension T of the web 10 falls within the range between the critical upper limit tension T _wick calculated in step S1 and the critical lower limit tension T _slip calculated in step S2. In addition, the position of the dancer roller 2b is controlled to change in the vertical direction by outputting a drive signal to the tension adjusting means 4 (step S8).

(Floating amount calculation step)
The web conveyance device 1 calculates the flying height h of the web 10 with respect to the free roller 2c or the driving roller 2d by the flying height calculation unit 76a of the shaft angle adjustment direction determination unit 76 during the conveyance of the web 10 (step S9 (1)). ).

(Axis angle adjustment direction judgment step)
Then, the shaft angle adjustment direction determination means 76b compares the magnitude relationship between the combined surface roughness σ of the free roller 2c or the drive roller 2d and the web and the flying height h of the web 10 with respect to these rollers 2. Here, when h> σ, that is, under the condition that the flying height of the web 10 with respect to the roller 2 is large and the frictional force between the roller 2 and the web 10 is small, as shown in FIG. An adjustment direction RV of the shaft angle (skew angle θ) is determined in a direction in which the shaft 20d of the drive roller 2d is perpendicular to the waveform straight line L generated above.
On the other hand, when h ≦ σ, that is, under the condition that the floating amount of the web 10 with respect to the roller 2 is small and the frictional force between the roller 2 and the web 10 is uniformly generated in the entire contact area between the roller 2 and the web 10. As shown in FIG. 7B, the angle (skew) of the shaft in a direction in which the shaft 20c of the free roller 2c or the shaft 20d of the driving roller 2d becomes an acute angle with respect to the straight line L of the waveform generated on the web 10. The adjustment direction RV of the angle θ) is determined (step S9 (2)).

Here, the reason for determining the adjustment direction of the skew angle θ with respect to the guide roller 2c or the driving roller 2d as described above will be described with reference to FIG. FIG. 7 is an explanatory diagram for explaining a method of controlling the guide roller 2c or the driving roller 2d when a waveform (a undulation phenomenon) that is a precursor of wrinkles occurs on the web. Here, images taken by the camera 3 are respectively shown, and a state in which the web 10 is conveyed on the guide roller 2c or the driving roller 2d from the upper side to the lower side in the drawing is shown.
In FIG. 7, for easy understanding, the skew angle of the guide roller 2c or the driving roller 2d is largely adjusted, but in actuality, the angle is gradually adjusted at an angle of 1 degree, 2 degrees, or the like.

First, when h> σ, the frictional force between the roller 2 and the web 10 becomes small. At this time, if there is misalignment, the tension at each position in the width direction of the web 10 becomes non-uniform, and the free roller 2c The contact area CA is biased to a portion where the distance from the drive roller 2d is large, and the tension at this portion increases. In the region where the tension is large, the flying height h is small and the frictional force is large.
As a result, as shown in FIG. 7A, a moment M is generated to rotate the web 10, and the web 10 is illustrated on the driving roller 2d positioned downstream in the example of FIG. As a result, the web 10 is deformed to generate a wave-like straight line L in the direction shown in FIG. In this case, the web angle is effectively adjusted by adjusting the angle of the shaft (skew angle θ) in the direction in which the shaft 20d of the drive roller 2d is perpendicular to the straight line L of the waveform generated on the web 10. The tension in each position in the width direction of 10 is made uniform, and the unevenness of the contact area CA between the free roller 2c and the driving roller 2d is eliminated. As a result, the entire frictional force is averaged, and the waviness phenomenon is canceled out to prevent the generation of wrinkles.

On the other hand, when h ≦ σ, the contact area CA between the roller 2 and the web 10 covers the entire width direction regardless of the distance between the free roller 2c and the drive roller 2d even if misalignment occurs. The frictional force between the roller 2 and the web 10 is uniformly generated over the entire contact area CA.
As a result, the frictional force _{F F} between the driving roller 2d and the web 10, of the direction component _{F F2} perpendicular to the web conveyance direction component _{F F1} and thereby, the latter component _{F F2,} example of FIG. 7 (b) Then, a force that moves the web 10 toward the left side of the drawing works, and the web 10 is deformed to generate a straight line L having a waveform in the direction of the drawing. In this case, the shaft angle (skew angle θ) is adjusted in a direction in which the shaft 20c of the free roller 2c or the shaft 20d of the drive roller 2d becomes an acute angle with respect to the straight line L of the waveform generated on the web 10. By correcting the free roller 2c and the drive roller 2d in parallel, the direction component _FF2 orthogonal to the web conveyance direction is canceled out. In this case, the frictional force between the roller 2 and the web 10 is originally generated uniformly in the entire contact area CA, so that the free roller 2c and the driving roller 2d are corrected in parallel, thereby causing the undulation phenomenon. Can be canceled to prevent the generation of wrinkles.

(Image analysis step)
First, the web conveyance device 1 inputs the image of the web 10 conveyed on the guide roller 2c, which is imaged by the camera 3, by the image input unit 73a of the image analysis unit 73 in time series in units of frames (step S10). ).
Then, the web conveying device 1 is input in step S9 by the waveform detecting means 73b in order to detect a waveform (a undulation phenomenon) that is a precursor to the occurrence of wrinkles and the approach direction of the straight line of the waveform to the guide roller 2c. The obtained image is analyzed (step S11).
Here, the web conveyance apparatus 1 determines whether the waveform straight line of the waveform was detected by the waveform detection means 73b (step S12).

(Axis angle control step)
If a straight line of the waveform is detected in step S11 (Yes), the web conveyance device 1 performs step S9 (with respect to the approach direction of the waveform (straight line) analyzed in step S10 by the shaft angle control means 74. By outputting a drive signal to the alignment adjusting means 5 so as to move the shaft 20c of the guide roller 2c or the shaft 20d of the drive roller 2d in the adjustment direction RV determined in 2), the guide roller 2c or the drive roller The skew angle of 2d is controlled (step S13).

As mentioned above, by controlling the skew angle of the guide roller 2c or driving roller 2d, it is possible to state shifts to a stable area S _T, to prevent the occurrence of wrinkles.
After the operation of step S13 or when the waveform is not detected in step S12 (No), the web conveyance device 1 returns to step S6 and continues the operation while the web 10 is being conveyed.

With the above operation, the web conveyance device 1 can stably convey the web 10 while preventing generation of wrinkles and slipping.
Here, the image analysis step and the shaft angle control step are executed after the tension control step, the flying height calculation step, and the shaft angle adjustment direction determination step. However, these steps are performed in the order described above. It is not limited. Moreover, it is good also as performing each operation | movement in parallel. In the critical tension calculating step, the order of step S1 and step S2 may be reversed or may be operated in parallel.

  According to the embodiment of the present invention configured as described above, the following operational effects can be obtained. That is, the web conveyance device 1 according to the embodiment of the present invention is based on the drive information indicating the predetermined drive condition in the conveyance path and the physical property value of the web 10 by the shaft angle adjustment direction determination unit 76. The flying height h of the web 10 on the driving roller 2d or the free roller 2c is obtained, and the optimum adjustment direction of the angles of the shafts 20d and 20c is determined based on the result. Further, the image of the web 10 conveyed on the web conveyance path is imaged by the imaging means 3. Then, the image analysis means 73 of the controller 7 detects, from the captured image, a straight line L that shows a waveform (wave phenomenon) that appears as a wave generated on the web 10, and the straight line L enters the roller 2 in the direction of entry. Is analyzed. Then, the alignment adjusting means 5 is controlled to drive the shaft 20d or 20c of the drive roller 2d or the free roller 2c in the direction determined by the shaft angle adjustment direction determining means 76.

  Further, in the shaft angle adjustment direction determination means 76, paying attention to the relationship between the flying height h of the web 10 and the combined surface roughness σ of the roller 2 and the web 10, and in an appropriate direction according to these relationships, An adjustment direction of the angle of the shaft 20d or 20c is determined. As a result, so-called misalignment is corrected to a state in which a waveform that is a precursor of wrinkles is attenuated, and generation of wrinkles is avoided.

Moreover, in the embodiment of the present invention, in determining the adjustment direction RV of the angle of the shafts 20d and 20c of the drive roller 2d or the free roller 2c, the combined surface roughness σ of the drive roller 2d or the free roller 2c and the web 10 The focus is on the magnitude relationship between the flying height h of the web relative to the roller. Then, when h> sigma, that is, under such conditions that the frictional force F _F is reduced with the flying height h is larger roller 2 and the web 10 of the web 10 to the roller 2 (FIG. 7 (a)), on the web 10 An adjustment direction RV of the shaft angle is determined in a direction in which the shaft of the drive roller 2d is perpendicular to the generated straight line L of the waveform.
On the other hand, when h ≦ σ, that is, the flying height of the web 10 with respect to the roller 2 is small, and the frictional force _FF between the roller 2 and the web 10 is generated uniformly over the entire contact area between the roller 2 and the web 10. Under the conditions (FIG. 7B), the shaft angle adjustment direction RV is determined so that the shafts 2d and 2c of the drive roller 2d or the free roller 2c are acute with respect to the straight line L of the waveform generated on the web 10. It is done.

  As described above, according to the web conveyance device 1 according to the embodiment of the present invention, so-called misalignment is corrected to a state in which a waveform that is a precursor of wrinkles is attenuated, and generation of wrinkles is avoided. Note that the presence or absence of a waveform that is a precursor of wrinkles is constantly monitored by the image analysis means 73. When the straight line L of the waveform is observed, the axes 20d and 20c are immediately set in the directions determined by the above means. It is driven and misalignment correction is performed.

  DESCRIPTION OF SYMBOLS 1, 1B: Web conveyance apparatus, 2: Roller, 2c: Guide roller (free roller), 2d: Drive roller, 3: Camera (imaging means), 4: Tension adjustment means, 40: Tension sensor (tension measurement means), 5: alignment adjusting means, 6: roller driving means, 7: controller, 70: storage means, 71: critical tension calculating means, 72: tension control means, 73: image analysis means, 74: shaft angle control means, 75: drive Control means, 76: shaft angle adjustment direction determination means

Claims (9)

A web conveying path constituted by a plurality of rollers including a driving roller and a free roller located upstream or downstream of the driving roller, an imaging means for imaging the web conveyed along the web conveying path, and Alignment adjusting means for adjusting the angle of the drive roller or the shaft of the free roller, and a controller,
The controller includes a flying height calculation unit that calculates a flying height of the web on the driving roller or the free roller based on driving information indicating a predetermined driving condition in the conveyance path and a physical property value of the web. ,
An axis angle adjustment direction determination means for determining an adjustment direction of the angle of the axis based on the calculation result of the flying height calculation means;
An image analysis unit that detects a straight line of a waveform generated on the web from the captured image captured by the imaging unit, and that analyzes an approach direction of the straight line to the roller;
A shaft angle for controlling the alignment adjusting means to drive the shaft in a direction determined by the shaft angle adjusting direction determining means in accordance with the approach direction of the straight line to the roller analyzed by the image analyzing means. And a web transfer device. In the shaft angle adjustment direction determining means, the shaft of the drive roller or the free roller is set against the straight line of the waveform generated on the web according to the relationship between the flying height of the web and the combined surface roughness of the roller and the web. The web conveyance device according to claim 1, wherein an adjustment direction of the angle of the shaft is determined in a direction that becomes a right angle or an acute angle. In the shaft angle adjustment direction determining means, when the relationship between the combined surface roughness σ of the driving roller and the web and the flying height h of the web with respect to the driving roller is h> σ, a straight line of a waveform generated on the web On the other hand, the adjustment direction of the angle of the shaft is determined in a direction in which the shaft of the driving roller is perpendicular,
When the relationship between the combined surface roughness σ of the driving roller or the free roller and the web and the flying height h of the web with respect to the driving roller is h ≦ σ, the driving is performed with respect to a waveform straight line generated on the web. The web conveyance device according to claim 2, wherein an adjustment direction of the angle of the shaft is determined in a direction in which the shaft of the roller or the free roller becomes an acute angle. A web transport method using a web transport device including a web transport path constituted by a plurality of rollers including a drive roller and a free roller located upstream or downstream of the drive roller,
A flying height calculating step for determining a flying height of the web in the driving roller or the free roller based on driving information indicating a predetermined driving condition of the conveyance path and a physical property value of the web;
A shaft angle adjustment direction determination step that determines an adjustment direction of the shaft angle of the drive roller or the free roller based on the calculation result of the flying height calculation step;
An image analysis step for detecting a straight line of a waveform generated on the web from the captured image obtained by imaging the web conveyed along the conveyance path, and analyzing an approach direction of the straight line with respect to the roller ;
Analyzed in the image analysis step, depending on the approach direction to said roller of said straight line, in the direction determined by the axis angle adjusting direction determination step, and characterized in that it comprises a shaft angle control step of driving said shaft Web transport method. In the shaft angle adjustment direction determination step, the shaft of the driving roller or the free roller is set against the straight line of the waveform generated on the web according to the relationship between the flying height of the web and the combined surface roughness of the roller and the web. The web conveying method according to claim 4, wherein an adjustment direction of the angle of the shaft is determined in a direction that becomes a right angle or an acute angle. In the shaft angle adjustment direction determination step, when the relationship between the combined surface roughness σ of the driving roller and the web and the flying height h of the web with respect to the driving roller is h> σ, a straight line of a waveform generated on the web On the other hand, an adjustment direction of the angle of the shaft is determined in a direction in which the shaft of the drive roller is perpendicular,
When the relationship between the combined surface roughness σ of the driving roller or the free roller and the web and the flying height h of the web with respect to the driving roller is h ≦ σ, the driving is performed with respect to a waveform straight line generated on the web. 6. The web conveying method according to claim 5, wherein an adjustment direction of the angle of the shaft is determined in a direction in which the shaft of the roller or the free roller becomes an acute angle. A web conveyance path constituted by a plurality of rollers including a driving roller and a free roller located upstream or downstream of the driving roller, and an alignment adjusting means for adjusting an angle of the shaft of the driving roller or the free roller. Web controller controller
A flying height calculating means for determining a flying height of the web on the driving roller or the free roller based on driving information indicating a predetermined driving condition of the conveyance path and a physical property value of the web;
An axis angle adjustment direction determination means for determining an adjustment direction of the angle of the axis based on the calculation result of the flying height calculation means;
An image analyzing means for detecting a straight line of a waveform generated on the web from an imaged image obtained by capturing the web conveyed along the conveyance path, and analyzing an approach direction of the straight line to the roller;
The shaft angle for controlling the alignment adjusting means to drive the shaft in the direction determined by the shaft angle adjusting direction determining means according to the approach direction of the straight line to the roller analyzed by the image analyzing means. The web conveyance control program characterized by including the control logic to function as a control means. In the shaft angle adjustment direction determining means, the shaft of the drive roller or the free roller is set against the straight line of the waveform generated on the web according to the relationship between the flying height of the web and the combined surface roughness of the roller and the web. The web conveyance control program according to claim 7, wherein an adjustment direction of the angle of the shaft is determined in a direction that becomes a right angle or an acute angle. In the shaft angle adjustment direction determining means, when the relationship between the combined surface roughness σ of the driving roller and the web and the flying height h of the web with respect to the driving roller is h> σ, a straight line of a waveform generated on the web On the other hand, the adjustment direction of the angle of the shaft is determined in a direction in which the shaft of the driving roller is perpendicular,
When the relationship between the combined surface roughness σ of the driving roller or the free roller and the web and the flying height h of the web with respect to the driving roller is h ≦ σ, the driving is performed with respect to a waveform straight line generated on the web. 9. The web conveyance control program according to claim 8, wherein an adjustment direction of the angle of the shaft is determined in a direction in which the shaft of the roller or the free roller becomes an acute angle.

Images