JP2585789B2 - Sheet transport device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention; (Industrial Application Field) The present invention relates to a photographic film or paper, or
The present invention relates to a sheet conveying apparatus for securely adsorbing and conveying a sheet having a photosensitive layer on the surface of electrophotographic plate making paper or the like without damaging the sheet.

(Prior Art) As a conventional apparatus for transporting a sheet of this type, for example, in a process of transporting the photosensitive surface of the sheet upward,
There is known a so-called console type projection system in which an image of a subject document arranged with an image surface to be photographed facing down above a transport path is projected and exposed on a sheet photosensitive surface and photographed. However, when the image surface of the document is arranged downward as described above, it is difficult to position the image surface to be photographed first because the image surface to be photographed is not known to the operator. Particularly, the document is a pasted document for creating a photoengraving, for example. In this case, the pasting portion may be broken or peeled off, and there is a problem that the photographing operation is performed without knowing this state. In general, an optical system for irradiating and projecting an original is disposed below the original placing surface. Therefore, when the size of the original to be photographed is large, the original placing surface is set high. As a result, there is a disadvantage that not only the device becomes large but also the workability is extremely reduced.

As a solution to the above-described disadvantage, for example, a sheet conveying device 100 in an electrophotographic plate making machine as shown in FIG.
Has been proposed by the present applicant. That is, this electrophotographic plate making machine includes a master paper supply unit 13 for accommodating roll-shaped plate-making paper (hereinafter, referred to as a master paper) 4 made of, for example, zinc oxide paper, and a photosensitive surface facing down from the master paper supply unit 13. 6 that cuts the supplied master paper 4 by a predetermined length by driving a driving motor M4, a corona charger 14 that charges the cut master paper 4, and a conveyance unit for the charged master paper 4. A belt 5 composed of a plurality of belts at a certain interval, rollers 15a and 15b wound around the belt 5 and driven by a driving motor M1, and a back surface (anti-photosensitive surface) of the master paper 4 are attracted and held. Chamber 16, a vacuum pump 17 for reducing the pressure in the vacuum chamber 16, and the supply of the master paper 4 A drive signal is output to a detector D4 to be detected, and a detection signal from the detector D4 to an electromagnetic valve 19 provided in the middle of a pipe 18 connecting the vacuum chamber 16 and the vacuum pump 17, and the electromagnetic valve 19 A sheet conveying device 100 including a driving unit 20 for controlling opening and closing, and a driving motor M3 provided in a lower part of the sheet conveying device 100 and placed on a document table 1 in a direction a in FIG. And scanning exposure means 3 for moving by driving and continuously exposing by slit scanning.

In such a configuration, an operation example will be described.
When the detector D4 detects the leading end of the master paper 4 supplied from the master paper supply unit 13 and inputs a detection signal to the driving means 20, the driving means 20 opens the electromagnetic valve 19, and the vacuum pump 17 operates the vacuum chamber 16 The pressure of the air inside the vacuum chamber 16 is reduced, and the master paper 4 is sucked by suction holes formed in a large number at intervals of the belt 5 on the surface of the vacuum chamber 16. Then, when the master paper 4 is conveyed by a predetermined amount in a state where the master paper 4 is adsorbed on the surface of the belt 5 by the rotation of the rollers 15a and 15b, the cutter 6 is cut into a predetermined length, and the cut master paper 4 is adsorbed and conveyed by the belt 5 again. I do. In this process, the corona charger 14 charges the master paper 4, the image light of the document 2 radiated from the scanning exposure unit 3 exposes the photosensitive surface of the master paper 4, and the exposed master paper 4 is transferred to the belt 5. It is conveyed in the direction of a developing unit (not shown). As described above, in the process of transporting the master paper 4 with its photosensitive surface facing downward, a so-called camera type photographing method is used in which an image of the document 2 placed with the image surface facing upward below the transport surface is photographed. According to this, since the document table 1 can be set downward, the workability is improved, the positioning of the document image to be photographed is easy, and the above-mentioned drawbacks of the control type are eliminated.

(Problems to be Solved by the Invention) In the above-described conventional sheet conveying apparatus, when the atmosphere of the sheet conveying apparatus is low in humidity and the master paper supplied from the master paper supply unit is curled as shown in FIG. However, the head of the master paper may fall without being adsorbed by the vacuum chamber, and particularly a narrow master paper is remarkable. Conventionally, in such a case, the inside of the electrophotographic plate making machine or the room where it is installed is humidified or air-conditioned. However, the installation of the humidifier or the air conditioner is costly, and the installation of the humidifier or the air conditioner in the electrophotographic plate making machine has a disadvantage that the plate making machine becomes large.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a sheet conveying apparatus capable of reliably adsorbing and conveying a sheet such as a curled master paper.

(Means for Solving the Problems) The present invention relates to a photographic film or paper, or
The present invention relates to a sheet conveying apparatus that reliably sucks and conveys a sheet having a photosensitive layer on a surface of electrophotographic plate making paper or the like without damaging the sheet.
A sheet conveying device configured to include a conveying unit that conveys the sheet, and an adsorbing unit that adsorbs the sheet; and a sheet conveying device that conveys the sheet while bringing the sheet into close contact with the conveying unit by an adsorbing action of the adsorbing unit. This is achieved by providing guide means that can move along the sheet, and performing the movement while supporting the leading end of the supplied sheet.

(Operation) In the sheet conveying apparatus of the present invention, the leading end of the master paper is supported by the guide means to correct the curl of the master paper so as to be flat, and in this state, the guide means and the master paper are separated. Since the master paper moves along the transporting means, the master paper can be reliably sucked and transported during the movement.

(Embodiment) FIG. 1 is a structural view showing an example of a sheet conveying apparatus according to the present invention in correspondence with FIG. 10, and the same components are denoted by the same reference numerals and description thereof is omitted. The sheet conveying device 200 is disposed between the scanning exposure unit 3 and the master paper 4 and in the vicinity of the master paper 4, and can be moved by a belt conveyor 7 in a direction b shown in the drawing parallel to the conveying direction of the master paper 4. 2. A long guide plate 8 as shown in FIG. 2 on which the leading end of the supplied master paper 4 is placed.
And numerical data on printing input from outside (length of master paper 4, width of document 2, distance between printing, etc.)
Pulsar 9 for checking the amount of movement of the guide plate 8 based on the
The pulser 10 for checking the transport amount of the master paper 4, the pulser 11 for checking the movement amount of the scanning exposure means 3, the fixed position detector D1 for detecting the right end of the guide plate 8 in the drawing, the left end and the right end of the scanning exposure means 3 in the drawing The motor M1 for driving the belt 5 and the motor M2 for driving the guide plate 8, while monitoring signals from the fixed position detectors D2 and D3 for detecting the respective parts and the detector D4 for detecting the leading end of the master paper 4, scan The drive of the drive motor M3 of the exposure means 3, the drive motor M4 of the cutter 6, and the drive of the electromagnetic valve 19 are controlled.
And a control device 12 for controlling ON / OFF of the light source 30 are provided in place of the conventional driving means 20.

The guide plate 8 also has a function as a light-shielding plate in two-side printing.

The case of performing the double-sided printing in such a configuration will be described with reference to the flowchart of FIG. 3, the time chart of FIG. 4, and the specific operation diagrams of FIGS. 5 (A) to (H). For example, when printing the same image A on two sides on the master paper 4 as shown in FIG. 6, the following numerical data (see FIGS. 6 and 7) is input to the control device 12.

L: Length of master paper 4 a: Width of original 2 (image A) w: Distance between printings l ₁ : Distance from cutter 6 to center of transport means l ₂ : Transport from fixed position detector D1 of guide plate 8 Distance obtained by subtracting the width of the guide plate 8 from the distance to the center of the means l ₃ : width of the guide plate 8 l ₄ : transport means from the optical axis when the scanning exposure means 3 is located at the fixed position detector D2 FIG. 7 is a diagram showing an initial state of the exposure surface. The tip of the master paper 4 is located at the cutter 6, and the right end of the guide plate 8 is located at the fixed position detector D1. Position to,
The scanning exposure means 3 has its left end shown in the figure at the fixed position detector D2, and the original 2 has its left end shown w /
It is located two spaces apart.

The controller 12 calculates the amount of transport of the master paper 4, the amount of movement of the guide plate 8, and the off position of the light source 30 based on the numerical data. Here, the transport amount of the master paper 4 refers to the distance from the cutter 6 to the leading end of the master paper 4, and the moving amount of the guide plate 8 refers to the distance from the fixed position detector D 1 of the guide plate 8 to the right end of the guide plate 8. The distance of
The off position of the light source 30 is the fixed position detector D2 of the scanning exposure means 3.
To the left end of the scanning exposure means 3.

First, the transport amount x ₁ of the master paper 4 and the transport amount x ₂ of the master paper 4 for the first and second exposures until the guide plate 8 starts to move while supporting the leading end of the master paper 4. and x ₃ the following equation (1) is calculated by the following formula (2) and the following equation (3).

x ₁ > l ₁ −l ₂ −l ₃ (1) Then, the following equation the amount of movement x ₅ and x ₆ of the guide plate 8 for the moving amount x ₄ of the guide plate 8 which moves while supporting the front end portion of the master paper 4 and the first and second exposure (4 ), The following equation (5) and the following equation (6).

x ₄ = K (4) x ₅ = l _2- (a + w) -α (5) x ₆ = l ₂ + l ₃ + α (6) where K is a constant value (for example, 350 mm) And α represents the length of a portion where the first exposure and the second exposure are performed in an overlapping manner, and is usually set to about 3 mm.

Then, to calculate the first and second times off position x ₇ and x ₈ of the light source 30 for exposure in the following equation (7) and the following equation (8) (step S1).

First, the drive motor M1 of the belt 5 is turned on (at the time
t ₁ ), the transport of master paper 4 is started (step
S2). When the detector D4 of the master paper 4 is turned on, the electromagnetic valve 19 is opened, and the air in the vacuum chamber 16 is depressurized by the vacuum pump 17 (steps S3 and S4). Conveying a master paper 4 to the guide plate 8, i.e., the conveyance amount of the master paper 4 to continue the conveyance until the calculated value x ₁ (step S5), and the guide plate at the time t ₂ the conveyance amount reaches the calculated value x ₁ 8 drive motor M2 is turned on (step S
6). Tip of the master paper 4 as shown in the time t ₂ Figure 5 (A) is in a state of being supported by the guide plate 8. When the guide plate 8 is moved along the belt 5 at the same speed as the conveying speed of the belt 5 while maintaining this state, the master paper 4 is sucked into the vacuum chamber 13 and conveyed by the belt 5 on the way. Become like Then, the moving amount of the guide plate 8 is a constant value x
Until ₄ (K) to continue the movement (step S7), and the amount of movement off the drive motor M2 of the guide plate 8 at a time t ₃ when was the constant value x ₄ (K) (step S8, fifth Figure (B)), whereas the master paper 4 to continue the conveyance until its conveying amount becomes the calculated value x ₂ (step S9), and the driving of the belt 5 at the time t ₄ when the amount of conveying becomes the calculated value x ₂ Motor M1
Is turned off (step S10). Then, to turn on at time t ₅ the drive motor M2 of the guide plate 8 in the reverse rotation (step S11). Movement of the guide plate 8 continues to place the detector D1 of the guide plate 8 is turned on (step S12), the drive position detector D1 of the guide plate 8 at a time t _6, which is on the guide plate 8 The motor M2 is turned off (step S13). Then, to turn on at time t ₇ the drive motor M2 of the guide plate 8 in the forward rotation (step S14). The guide plate 8 will continue to move until the moving amount is the calculated value x ₅ (step S15), and
Movement amount off the drive motor M2 of the guide plate 8 at the time point t ₈ became calculated value x ₅ (step S16). The At time t ₈ becomes positioned as shown in FIG. 5 (C), the baking ready of the first surface. Subsequently, a drive motor of the scanning exposure unit 3
M3 turn on the light source 30 as well as one (time t _8), starts moving scanning exposure device 3 (step S17), the first surface burn (FIG. 5 (D)). Then, continued exposure to the OFF position of the light source 30 becomes the calculated value x ₇ (step S18), and
OFF position of the light source 30 turns off the light source 30 at time t ₉ became calculated values x ₇ (step S19, FIG. 5 (E)). Movement of the scanning exposure means 3 continues to position detector D3 scanning exposure device 3 is turned on (step S20), the scanning exposure at the time point t ₁₀ to a fixed position detector D3 scanning exposure device 3 is turned on Means 3
The driving motor M3 is turned off (step S21). Then the drive motor M1 of the belt 5 is turned on (time t _10),
Start conveyance of master paper 4 (step S2
2). The transport amount is to continue the conveyance until the length L of the master paper 4 (step S23), turns off the drive motor M1 of the belt 5 at the time point t ₁₁ where the amount of conveying becomes the length L of the master paper 4 (Step S24) The drive motor M4 of the cutter 6 is turned on to cut the master paper 4 (Step S25). After this Katteingu is terminated (time t _12), and turns on the drive motor M1 of the belt 5 (time t _12), restarts the conveyance of the master paper 4 (step S26). Conveyance amount from time t ₁₂ will continue the transfer until the calculated value x ₃ (step S27), and turns off the drive motor M1 of the belt 5 at the time point t ₁₃ where the amount of conveying becomes the calculated value x ₃ ( Step S28). The drive motor M2 of the guide plate 8 is turned on at this time t ₁₃ (step S29), and starts the movement of the guide plate 8. The amount of movement continues to move until the calculated value x ₆ (step S30), the amount of movement to turn off the drive motor M2 of the guide plate 8 at the time point t ₁₄ became calculated value x ₆ (step S31) . The At time t ₁₄ becomes positioned as shown in FIG. 5 (F), the baked ready for the second surface. Followed by turning on the light source 30 as well as to turn on the drive motor M3 scanning exposure device 3 (time t _14), (this time moving to the left from the illustrated right) movement of the scanning exposure means 3 starts ( Step S32), the second surface is printed (FIG. 5 (G)). Then, continued exposure to the OFF position of the light source 30 becomes the calculated value x ₈ (step S33), (step S34 with the OFF position of the light source 30 is a light source 30 off when t ₁₅ became Calculated x ₈ 5 (H)), the driving motor M1, the developing motor and the pre-etching motor of the belt 5 are turned on (step S35). Movement of the scanning exposure means 3 continues to place the detector D2 scanning exposure device 3 is turned on (step S36), the scanning exposure at the time point t ₁₆ to a fixed position detector D2 scanning exposure device 3 is turned on The driving motor M3 of the means 3 is turned off (step S37). On the other hand, the exposed master paper 4 conveyed from the belt 5 is developed by the developing unit (step S38). Master paper 4 Check the drive motor M2 of the guide plate 8 while turning off the drive motor M1 of the belt 5 at the time t ₁₇ which is conveyed to the developing unit (step S39, S40), movement of the guide plate 8 ( At this time, the movement from the left to the right in the figure) is started. This movement continues until the position detector D1 of the guide plate 8 is turned on (step S41), the drive motor M2 of the guide plate 8 at a time t ₁₈ that position detectors D1 of the guide plate 8 is turned on Is turned off (step S42). On the other hand, the developed master paper 4 conveyed from the developing section is pre-etched by the pre-etching section (step S43), and the developing motor and the pre-etching motor are turned off (time point t ₁₉ ), and all the processing ends. .

Next, in the case of one-side printing (normal plate making), the eighth
This will be described with reference to the flowchart of FIG. 9 and the time chart of FIG. In this case, the control device 12 calculates the transport amounts x ₁ , x _{3 of} the master paper and the travel amount x ₄ of the guide plate 8 using the above equations (1), (3), and (4) (step S51). .
Then, the drive motor M1 of the belt 5 is turned on (at the time
t _21), to start the conveyance of the master paper 4 (step S52). When the detector D4 of the master paper 4 is turned on, the electromagnetic valve 19 is opened, and the air in the vacuum chamber 16 is depressurized by the vacuum pump 17 (steps S53 and S5).
Four). Conveying a master paper 4 to the guide plate 8, i.e., the conveyance amount of the master paper 4 to continue the conveyance until the calculated value x ₁ (step S55), the guide plate at the time t ₂₂ the conveyance amount reaches the calculated value x ₁ The drive motor M2 of No. 8 is turned on (step S56). At this point in time t ₂₂ master paper 4
Is supported by the guide plate 8. When the guide plate 8 is moved along the belt 5 at the same speed as the conveying speed of the belt 5 while maintaining this state, the master paper 4 is sucked into the vacuum chamber 13 and conveyed by the belt 5 on the way. Become like And
The amount of movement of the guide plate 8 continues to move until the constant value x ₄ (K) (step S57), the driving of the guide plate 8 at the time point t ₂₃ the amount of movement becomes constant value x ₄ (K) Motor M2 is turned off (step S58), while the master paper 4 continues to be transported until the transport amount reaches the length L of the master paper 4 (step S59), and the transport amount reaches the length L of the master paper 4. Turn off the drive motor M1 of the belt 5 at the time t ₂₄ was (step S60). Same time t
_{At 24} , the drive motor M2 of the guide plate 8 is turned on by reverse rotation (step S61). The movement of the guide plate 8 continues until the fixed position detector D1 of the guide plate 8 is turned on (step S6).
2), the time t when the fixed position detector D1 of the guide plate 8 is turned on
_{In step 25} , the drive motor M2 for the guide plate 8 is turned off (step S63). Then, the drive motor M4 of the cutter 6 is turned on to cut the master paper 4 (step S64). After the cutting is completed (time t _26), and turns on the drive motor M1 of the belt 5 (time t _26), resume the conveyance of the master paper 4 (step S65). Conveyance amount from time t ₂₆ will continue the transfer until the calculated value x ₃ (step S66), and turns off the drive motor M1 of the belt 5 at the time point t ₂₇ where the amount of conveying becomes the calculated value x ₃ ( Step S6
7). Then with turning on the driving motor M3 scanning exposure device 3, the light source 30 is turned on (time t _27), to start the movement of the scanning exposure means 3, baked image (step S6
8). Then, the driving motor M1 of the belt 5 as well as turning off the drive motor M3 and the light source 30 of the scanning exposure means 3 at the exposure end time t _28, to turn on the developing motor, the Purietchi motor. Developing the master paper 4 already exposure, which has been conveyed from the belt 5 by the developing unit (step S69), the drive motor M1 of the belt 5 off at t _29, which conveys the master paper 4 to the developing unit, the developing been came the developed master paper 4 conveyed from the parts to Purietchi with Purietchi unit (step S70), and the developing motor and off Purietchi motor (time t _30), all processing is terminated.

Effect of the Invention As described above, according to the sheet conveying apparatus of the present invention, the sheet can be conveyed reliably only by providing the guide means of a simple mechanism, and therefore, a compact and low-cost electrophotographic plate making machine is provided. Can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of a sheet conveying apparatus according to the present invention, FIG. 2 is a perspective view of a main part thereof viewed from below, and FIG.
FIGS. 8, 8 and 4 are flow charts and time charts for explaining an operation example of the sheet conveying apparatus of the present invention, and FIGS. 5A to 5H show specific examples of the operation. FIG. 6 is a view showing an example of two-sided printing, FIG. 7 is a view for explaining numerical data input to a control device of the sheet conveying apparatus of the present invention, and FIG. 10 is an example of a conventional sheet conveying apparatus. FIG. 11 is a schematic view of the main part seen from below. 1 ... original table, 2 ... original, 3 ... scanning exposure means, 4 ...
... master paper, 5 ... belt, 6 ... cutter,
7 ... belt conveyor, 8 ... guide plate, 9, 10, 11 ...
Pulsars, M1, M2, M3, M4 ... Drive motors, 12 ... Control devices, 13 ... Master paper supply unit, 14 ... Corona chargers, 15a, 15b ... Rollers, 16 ... Vacuum chambers, 17 … Vacuum pump, 18… Piping, 19… Electromagnetic valve, 20… Driving means, 30… Light source, D1, D2, D3… Fixed position detector, D4… Detector, 100, 200… Sheet transport apparatus.

Claims (1)

(57) [Claims] 1. A sheet conveying apparatus comprising: conveying means for conveying a sheet; and suction means for adsorbing the sheet, wherein the sheet is conveyed while being brought into close contact with the conveying means by an adsorbing action of the adsorbing means. A sheet conveying device provided with guide means movable along the conveying means, wherein the guide means performs the movement while supporting a leading end of the supplied sheet.