JPH04260555A - Sheet detecting mechanism - Google Patents

Abstract

PURPOSE:To precisely detect the presence of a sheet by compensating the deflection of a drum between a first drum which always makes contact with the drum and a second roller which separatably make contact with a sheet held between the drum and a conveyer belt so that the presence of the sheet can be detected by a displacement of the second roller. CONSTITUTION:A photosensor 68 fixed to a support member 66 for a first roller 58 which makes always contact with a drum 24 is energized or deenergized by a detection piece 80 attached to a second roller 72 adjacent to the first roller 58 so as to compensate a deflection of a drum 24. With this arrangement, the displacements of the second roller 72 which is displaced by making contact with a photosensitive material 32 as a sheet fed by the drum 24 and a conveyer system 28 making contact with the periphery of the drum 24 is detected by the photosensitive sensor 68, thereby it is possible to surely detect the presence of the photosensitive material 32.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention provides sheet body detection for detecting whether or not a sheet body exists between the drum and a conveyor belt when conveying a sheet body such as a film using a rotating drum. Regarding the mechanism.

0002

2. Description of the Related Art FIG. 5 shows a conveyance apparatus equipped with a sheet body detection mechanism according to the prior art for conveying a sheet body such as a photographic material (for example, an X-ray film, a graphic arts film, etc.). This conveyance device 2 includes a suction cup 6 connected to a vacuum supply source (not shown) for suctioning single sheet bodies F stacked and stored in a supply magazine 4;
A conveying mechanism 8 is provided for conveying the sheet body F attracted by the suction cup 6 to the next process (for example, exposure, development, etc.).

[0003] In this conveyance mechanism 8, drums 10a, 10
A belt 14 is stretched between a plurality of rollers 12a to 12c arranged around the drum 10a,
A plurality of rollers 16a to 16 arranged around 10b
A belt 18 is stretched between the belts c to form a conveyance system. A leaf 19 detects whether a plurality of sheets F are conveyed to the drum 10a.
A microswitch 17 is provided.

0004

In the above-mentioned conveyance mechanism 8, it is preferable that the drum 10a, which the leaf 19 of the microswitch 17 for detecting the sheet F comes into contact with, is formed as accurately as possible. Drum 10 in reality
The outer periphery of the drum 10a is often slightly deformed without being perfectly circular, and is eccentric with respect to the axis, causing the drum 10a to run out. Therefore, the leaf 19 of the microswitch 17 that comes into contact with the periphery of the drum 10a is displaced,
As a result, even though the sheet body F has not yet been conveyed to the drum 10a, there is a possibility that the sheet body F may be erroneously detected as having been conveyed. On the other hand, a method of detecting the sheet body using an optical sensor is also considered, but if the sheet body is a photosensitive material such as a film, there is a possibility that the sheet body will be exposed to this light, so it is not practical.

The present invention was made to solve this type of problem, and includes a detector disposed on a first roller that is always in contact with the drum, and a detection piece on a second roller that can be separated from the drum. It is an object of the present invention to provide a sheet body detection mechanism that corrects the amount of deflection of a drum and makes it possible to reliably detect a conveyed sheet body by the displacement of a second roller.

[0006]

Means for Solving the Problems In order to achieve the above object, the present invention includes a rotating drum and a conveyor belt circumferentially surrounding the drum, the belt being held between the drum and the conveyor belt. , a sheet body detection mechanism that detects a sheet body conveyed in a predetermined direction, a first roller that is constantly in contact with the drum, and a support body that is connected to a first shaft member that holds the first roller; a detector fixed to the support; a second roller that abuts the drum so that it can be separated when the sheet body enters; a second shaft member that holds the second roller; It is characterized by comprising a detection piece that energizes or deenergizes the detector by displacing the second roller when a sheet enters between the detector and the second roller.

[0007]

[Operation] In the above-mentioned sheet body detection mechanism according to the present invention, the detector fixed to the support of the first roller that is in constant contact with the drum is replaced by the detection piece provided on the second roller that is displaced by the entry of the sheet body. An energizing or deenergizing action is performed to correct the amount of vibration of the drum. This makes it possible to accurately know whether or not there is a sheet to be conveyed without erroneously detecting it.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The sheet body detection mechanism according to the present invention will be described in detail below with reference to embodiments and the accompanying drawings.

[0009] In FIGS. 1 to 4, reference numeral 20 is
1 shows a sheet conveyance device equipped with a sheet detection mechanism according to the present embodiment. This sheet body conveying device 20 includes a suction mechanism 22 that sequentially suctions and holds stacked sheet bodies and conveys them.
, a belt-shaped first conveyance system 26 disposed on one side of the drum 24 that can be rotated in forward and reverse directions, and a belt-shaped second conveyance system disposed on the other side of the drum 24. It basically consists of system 28.

The suction mechanism 22 includes a suction cup 34 connected to a vacuum supply source for sequentially suctioning and holding the photosensitive materials 32, which are sheets stacked in the supply magazine 30.
Equipped with

[0011] In this embodiment, the supply magazine 30
is used, but it is not necessarily limited to this, and any structure that allows the photographic material 32 to be stacked and placed may be used.

A conveying mechanism shown in FIG. 1 is provided to send the photosensitive material 32 picked up by the sucking mechanism 22 and taken out from the supply magazine 30 to the outlet. The drum 24 in this transport mechanism is cylindrical and has a mirror-finished surface, and the length of the drum 24 in the circumferential direction is preferably at least one time the length of the photographic material 32 to be transported. However, it is not necessarily limited. A rotary drive source 36 for forward and reverse rotation is provided below the drum 24, and the drum 24 and the rotary drive source 36
A belt 40 is attached to the pulleys 38a and 38b provided respectively in the
is passed over.

On one side of the drum 24, the drum 2
Belts 44a to 44c are stretched between a plurality of rollers 42a to 42d arranged around the first conveyance system 26.
form. In order to reliably receive the photosensitive material 32 conveyed from the suction mechanism 22 between the rollers 42 a and 46 on the suction mechanism 22 side of the first conveyance system 26 , sub belts 48 a and 48 b are wrapped around them. Similarly, on the other side of the drum 24, a belt 52a is placed between a plurality of rollers 50a to 50d disposed around the drum 24.
52c to 52c are stretched to form the second conveyance system 28.

An inlet 54 is formed between the first conveyance system 26 and the vicinity of the upstream side of the drum 24, while an outlet 56 is formed between the second conveyance system 28 and the vicinity of the downstream side of the drum 24. A first roller 58 is mounted on the drum 24 near the outlet 56.
are always in contact with each other. This first roller 58 is pivotally supported by a first shaft member 60. One end of the first shaft member 60 is fixed to one outer frame of the sheet conveying device 20, and the other end is attached to a long hole 64 defined in the other outer frame 62, as can be understood from FIG. and is connected to one end of the support body 66. Note that an optical sensor 68 consisting of a light emitting section 68a and a light receiving section 68b is disposed at the other end of the support 66. A coil spring 70 whose one end is fixed to the outer frame 62 is attached to the first shaft member 60, and the tensile force of the coil spring 70 causes the first roller 58 to always come into contact with the drum 24.

[0015] Furthermore, the belt 5 constituting the second conveyance system 28
In the vicinity of the first roller 58 between 2a and 52b, a second roller 72 for detecting the amount of displacement due to the entry of the photographic material 32 contacts the drum 24 in a separable manner. This second roller 72 is pivotally supported by a second shaft member 74. The second shaft member 74 has one end fixed to one outer frame of the sheet conveying device 20 and the other end fixed to the other outer frame 6.
It passes through a large hole 78 defined in 2 and is fixed to the detection piece 80. One end of the detection piece 80 is inserted between the light emitting part 68a and the light receiving part 68b of the optical sensor 68, which is a detector disposed at the end of the support body 66, and the other end is inserted between the light emitting part 68a and the light receiving part 68b. It is penetrated by the uniaxial member 60. When the photosensitive material 32 is not detected, it remains parallel to the first shaft member 60. Note that although the optical sensor 68 is described as a preferred embodiment as a sensor,
It is also possible to use a linear encoder, potentiometer, etc. that corresponds to the movement of the first shaft member 60 or the second shaft member 74 and detects the amount of displacement thereof. Thereby, the presence or absence of the photographic material 32 can be accurately detected based on the amount of displacement.

A plurality of guide plates 8 are provided near the outlet 56.
2a to 82c and rollers 84a and 84b are provided, and play the role of guiding the photosensitive material 32 to an automatic developing device (not shown).

Next, the operation of the sheet conveying device 20 constructed as described above will be explained.

After the supply magazine 30 is loaded into the sheet conveying device 20, the suction cup 34 is displaced toward the supply magazine 30, approaches the photosensitive material 32, and is held at a predetermined height relative to the photosensitive material 32. Start suction and press the suction cup 34
is sucked up without contacting the photographic light-sensitive material 32, and the photographic light-sensitive material 32 is suctioned.

When the suction cup 34 reaches a predetermined position, it rotates within a predetermined angular range and sends out the photographic material 32 suctioned and held by the suction cup 34 onto the sub-belts 48a, 48b. The adsorption effect of the photosensitive material 32 is released.

The photosensitive material 32 is held between the first conveying system 26 and the drum 24, which are rotating in the direction of arrow a in the figure, and moves on the surface of the drum 24, and then transferred to the second conveying system 28.
guided by. When the photosensitive material 32 is not being conveyed to the drum 24, the first roller 58, which is in constant contact with the drum 24, and the second roller 58, which is disposed near the first roller 58,
Since the amount of displacement of the roller 72 with respect to the drum 24 does not change, the first shaft member 60 and the second shaft member 74 are displaced in parallel, and the detection piece 80 maintains a state in which the light source of the optical sensor 68 is shielded from light. That is, the optical sensor 68 disposed on the support body 66 of the first roller 58 and the detection piece 8 fixed to the second roller 72
0 always maintains a constant distance even if the drum 24 oscillates (see FIG. 4).

When the photosensitive material 32 is conveyed to the drum 24, the second roller 72 is displaced by the thickness of the photosensitive material 32, and the second shaft member 74 is moved toward the sheet conveying device 20.
The detection piece 80 is moved toward the front in FIG. 3 through the hole 78 defined in the outer frame 62 of the optical sensor 68 to release the light-blocking state of the optical sensor 68. In this case, since the first roller 58 is in contact with the circumferential surface of the drum 24, the first shaft member 60 and the second
The shaft member 74 is in a twisted state.

That is, the first roller 58 and the second roller 72 are displaced in accordance with the amount of deflection of the drum 24, and only the second roller 72 is displaced with respect to the first roller 58 due to the thickness of the photosensitive material 32. . Therefore, the presence or absence of the photographic material 32 can be accurately detected.

Note that even if the starting end of the photographic light-sensitive material 32 is curved in a curled shape or there is a difference in the thickness of the photographic light-sensitive material 32, the photographic light-sensitive material 32 is transferred between the first conveyance system 26 and the second conveyance system 26.
Since the sheet is conveyed while being held between the belts 44a to 44c and 52a to 52c of the conveying system 28, the sheet conveying device 20 is not stopped depending on whether or not the sheet is curled.

Next, the sheet detection mechanism detects the photographic material 3.
When the end of drum 2 is detected, the drum 2 moves in the direction of arrow b in the figure.
4 is reversely rotated to transport the photographic material 32 to the exit port 56 on the terminal side.
Remove from. In this case, the photographic material 32 is in an inverted state. Then, the terminal end of the photographic light-sensitive material 32 is connected to the second
When released from the conveyance system 28, the photosensitive material 32 is guided between the guide plates 82a to 82c while contacting the belts 52a to 52c of the second conveyance system 28, and is sent to an automatic developing device (not shown). The photosensitive material 32, whose back surface has been suctioned by the suction cup 34, is turned over by the drum 24, the first conveyance system 26, and the second conveyance system 28.

[0025]

As described above, the sheet detection mechanism according to the present invention has the following effects and advantages.

[0026] The amount of vibration of the drum is corrected by a detector fixed to the support of the first roller that is always in contact with the drum, and a detection piece that is disposed on the shaft of the second roller that is in contact with the drum in a separable manner. Therefore, the presence or absence of the sheet sandwiched between the drum and the conveyor belt can be reliably detected.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a sheet conveyance device using a sheet detection mechanism according to the present invention.

FIG. 2 is a schematic longitudinal sectional view of a sheet conveyance device using a sheet detection mechanism according to the present invention.

FIG. 3 is a partially omitted perspective explanatory view for explaining the operation of the sheet body detection mechanism according to the present invention.

FIG. 4 is a partially omitted explanatory diagram showing displacement states of the first roller, second roller, and detection piece due to eccentricity of the drum in the sheet body detection mechanism according to the present invention.

FIG. 5 is a schematic vertical cross-sectional view of a conveyance device equipped with a conventional sheet body detection mechanism.

[Explanation of symbols]

20... Sheet body conveyance device 22...Adsorption mechanism 24...Drum 26...First conveyance system 28...Second transport system 32...Photographic material 34...Suction cup 36...Rotary drive source 44a-44c...Belt 52a-52c...Belt 54…Carry-in entrance 56...Export exit 58...first roller 60...First shaft member 66...Support 68... Optical sensor 72...Second roller 74...Second shaft member 80...Detection piece

Claims (1)

[Claims] 1. A sheet body detection mechanism comprising a rotating drum and a conveyor belt circumferentially surrounding the drum, and detects a sheet body held between the drum and the conveyor belt and conveyed in a predetermined direction. , a first roller that is in constant contact with the drum; a support that is connected to a first shaft member that holds the first roller; a detector that is fixed to the support; When a sheet body enters between a second roller that comes into contact with the second roller such that it can be separated when the body enters, a second shaft member that holds the second roller, and the drum and the second roller, the second roller A sheet detection mechanism comprising: a detection piece that energizes or deenergizes the detector by displacement of two rollers.