JP2667112B2 - Image recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording apparatus for drawing a desired image on a photosensitive material, and more particularly to an image recording apparatus for fixing and holding a photosensitive material on a rotating drum.

[0002]

2. Description of the Related Art In a conventional image recording apparatus of this type, a decompression mechanism such as a blower depressurizes an inner chamber of a hollow cylindrical rotary drum having an adsorbing portion on an outer peripheral surface thereof through a pipe provided with a check valve. I do. Then, the printing plate is fed so as to be in contact with the outer peripheral surface of the rotating drum, and subsequently the rotating drum rotates at a low speed, whereby the printing plate is wound around the outer peripheral surface of the rotating drum. As the pressure reducing means continues to operate, the inner chamber of the rotating drum maintains a reduced pressure state, and in this state, the image drawing mechanism records a desired image on the photosensitive material while being driven to rotate.

[0003]

However, the prior art having such a structure has the following problems.

That is, since the printing plate is generally a thin plate made of aluminum and having a thickness of about 0.3 mm, the printing plate has a certain degree of rigidity. In the method of winding and holding the printing plate having this rigidity, when the printing plate is not normally wound around the suction surface of the rotating drum, or when a check valve provided in the piping has a failure. When the pipe connected to the decompression means is damaged, the inner chamber of the rotary drum cannot maintain the negative pressure required for suction of the printing plate. There is a problem that the printing plate is scattered due to rigidity.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide an image recording apparatus capable of preventing a printing plate wound around a rotating drum from scattering.

[0006]

The present invention has the following configuration in order to achieve the above object. That is, an image recording apparatus according to the present invention has an inner chamber, and has an opening communicating with the inner chamber on the surface, and a rotating drum for mounting a photosensitive material at a position where the opening is installed on the surface. A decompression means for decompressing the inner chamber of the rotary drum via a pipe, a check valve provided in the middle of the pipe, for maintaining a depressurized state of the inner chamber, and In an image recording apparatus having a recording unit for recording an image on a photosensitive material mounted on a rotating drum, a first control unit for ending the decompression by the decompression unit, and a decompression of the decompression unit by the first control unit. After being terminated, when a predetermined time has elapsed, an internal pressure detecting means for detecting a pressure in the inner chamber and issuing a detection signal, and when the detection signal indicates that the internal pressure of the rotating drum exceeds a predetermined pressure, Record It is characterized in that and a second control means for prohibiting the image recording by means.

[0007]

The operation of the present invention is as follows. That is,
After the photosensitive material is mounted on the rotating drum and then the pressure reducing means is stopped by the first control means, the internal pressure detecting means outputs a detection signal when a certain period of time has elapsed. The second control means determines whether there is an abnormality in the internal pressure of the drum based on the detection signal, and if there is an abnormality, inhibits the image recording process.

[0008]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is an exploded perspective view showing a schematic configuration of a rotary drum portion of an image recording apparatus according to an embodiment. FIG. 2 is a sectional view of a mechanism relating to detection of an internal pressure of the rotary drum. ) Shows the case where the internal pressure is almost atmospheric pressure, and FIG.
Indicates a case where the internal pressure is a negative pressure.

In FIG. 1, reference numeral 1 denotes a rotating drum. The rotating drum 1 is a hollow cylindrical member and has a space inside (inner chamber 2).
Has, on the outer peripheral portion and a pressing member 3 ₂ After for pressing the pressing member 3 ₁ and the rear end portion front for holding down the front end portion of the plate fed from the A direction. The two pressing members constitute a printing plate holding mechanism 3 in a pair, of the plate by energizing the pressing member 3 ₂ rear springs (not shown) and the support members 3 ₁ before the outer peripheral surface of the rotary drum 1 The both ends are pressed and fixed.

[0011] A between the front holding member 3 ₁ holding the rear and member 3 _2, parts rotary drum 1 adsorbs plate,
Grooves 4 ₁ a depth of about 1mm is formed in a lattice shape, the groove 4
The _{portion 1} intersect, the through-hole 4 ₂ is formed leading to the inner chamber 2 of the rotary drum 1. They form a suction unit 4, since only the pressing member 3 ₂ rear front holding member 3 ₁ to be difficult to stably held the plate S on the outer circumferential surface of the rotary drum 1 by the rigidity of the plate S It is arranged.

[0012] One of the rotary shaft rotary drum 1, the through-holes 5 ₁ spindle 5 with being communicatively connected to the inner chamber 2, on the other, a rotary drum 1 for forward and reverse driving motor 6
Is mounted. The main shaft 5 and the rotating shaft of the motor 6 are rotatably supported by a bearing base 8 via a bearing 7. The bearing stand 8 is attached to a gantry 9.

The main shaft 5 has a check valve 1 that opens and closes only in one direction to close the inner chamber 2 in order to maintain the reduced pressure state of the inner chamber 2.
0 ₂ and the valve seat 10 _first holder 10 ₃ through is screwed. Holder ₁₀₃ is rotatably through the sealing material is connected to one end of the L-shaped blower pipe 11, the other end of the blower pipe 11 is connected to the blower 12 is a pressure reducing means such as a vacuum pump . Further, the blower pipe 11 is attached to the frame 9 by the tube support member 11 _1.

The check valve 10 of the two side walls of the rotary drum 1
_{On the} side where ₂ is attached, an internal pressure detection unit 20 that is displaced in accordance with the pressure of the internal chamber 2 is provided.

[0015] In FIG. 2, reference numeral 20 ₁ denotes a pressure introduction hole for introducing the pressure of the inner chamber 2 to the pressure detection unit 20, from the pressure introducing hole 20 ₁ in the main shaft 5 side through holes for the guide there shaft hole 20 ₂ is formed stepped. The stepped portion of the shaft hole 20 ₂ is disposed sliding bearing 20 _3, The slide bearing 20 _3, the shaft 20 ₄ is inserted through the compression coil spring 20 _5. This compression coil spring 20 ₅ is used a spring with a suitable strength in accordance with the internal pressure so as to be substantially fully contracted when a normal internal pressure. Pressure introduction hole 20 ₁ and the shaft hole 20
The region covering the _2, the packing 20 _6, Roahoruda 20
₇ , diaphragm 20 ₈ and upper holder 20 ₉
Are fixed on the side wall of the rotating drum 1 with screws. Central portion of the diaphragm 20 ₈ is screwed to the shaft 20 ₄ with L-shaped sensing plate 21.

A position opposed to the internal pressure detecting section 20;
A groove-shaped photosensor 30 for detecting that the sensing plate 21 has protruded is provided on the bearing base 8 via a sensor support member 31 at a position where the tip of the sensing plate 21 protrudes.

The present embodiment further includes a recording head (not shown) controlled by the controller 50, and a desired image is formed on the plate S on the rotating drum 1 rotating at a high speed by using the recording head. It is formed.

Referring now to FIG. This figure is a block diagram of a control device related to the internal pressure detection.

In the figure, reference numeral 50 denotes a controller comprising a CPU and a memory, which is provided with a timer 51 capable of setting an appropriate time value in advance, for controlling the forward / reverse drive of the motor 6 and for turning on / off the blower 12. The control and the control of a recording head (not shown) are performed, and the displacement state of the internal pressure detecting unit 20 is detected via the photo sensor 30. Further, it outputs a control signal to the motor 6, the blower 12, and the recording head according to the detected internal pressure state of the rotating drum 1, and outputs an alarm signal and the like to the control console 60.

Next, a description will be given with reference to a flowchart of FIG. However, the printing plate S is fed in a state of contact with the outer peripheral surface of the rotary drum 1 from the direction A, are already inserted in the member 3 ₁ holding the front end portion ago are clamped fixed by the transport mechanism. This processing is executed by the controller 50.

In step S1, the controller 50 controls the blower 12 to be turned on to operate it, and sucks and discharges air from the inner chamber 2 of the rotary drum 1. The state of the internal pressure detecting unit 20 at this time corresponds to (a) of FIG.

In step S2, while rotating the motor 6 in the normal direction to wind the plate S around the suction section 4, information from a rotary encoder (not shown) in the motor 6 is obtained, and it is determined whether the motor 6 has been rotated to a predetermined angle. (Step S3). That is, it is determined based on the rotation angle of the motor 6 that the plate S has been wound around the rotary drum 1.

After the motor 6 rotates by a predetermined angle, the motor 6 is stopped, and the rear end of the printing plate S is moved by the conveying mechanism to the rear pressing member 3 _2.
And inserted and fixed. At this time, the printing plate S
Is absorbed and there is no other suction leakage, the inner chamber 2
There therefore is maintained at a predetermined negative pressure, the diaphragm 20 ₈ is drawn in the direction of the inner chamber 2 becomes the state of FIG. 2 (b).

In step S4, the motor 6 is controlled to rotate the rotating drum 1 at a low speed, so that the photo sensor 30 is stopped at a position where the sensing plate 21 of the internal pressure detecting section 20 can be detected. Then, the blower 12 that is depressurizing the inner chamber 2 is turned off and stopped, and the depressurizing operation is stopped (step S5). Next, the timer 51 is operated to count a preset time value (step S6). Here, it is assumed that 10 seconds is set as an example.

In step S7, the timer 51 counts 10 seconds, and sends a time-up signal to the controller 50 when the timer 51 ends (time-up).

In step S8, the controller 50, which has received the time-up signal from the timer 51,
The voltage of the output terminal of the photo sensor 30 is detected in order to detect the displacement, and the process branches in step S9 according to the state. When the printing plate S is normally held by suction (FIG. 2B), that is, when the inner chamber 2 of the rotary drum 1 holds a negative pressure necessary for suction, the sensing plate 21 is It does not block 30 light paths. Therefore, since the light receiving unit detects light from the light emitting unit and outputs a predetermined voltage to the output terminal, it is determined that the internal pressure is normal. Thereafter, when the operator instructs the console 60 to start image recording, the blower 12 operates again, and a control signal is sent to the motor 60 and the recording head to execute image recording processing (steps S12, S13, S1).
4).

On the other hand, when the printing plate S is not wound up on the rotating drum 1 normally or when the blower pipe 11 is damaged, the negative pressure in the inner chamber 2 cannot be maintained and the pressure is almost atmospheric pressure. , The sensing plate 21
There are pushed outward by the compression coil spring 20 _5.
Therefore, the sensing plate 21 is
Since the optical path of 0 is blocked, almost zero voltage is output to the output terminal of the photo sensor 30, and it is determined that the internal pressure is abnormal, and the process branches to step S10.

In step S10, an alarm device or an alarm lamp provided on the console 60 is operated to notify the operator of the occurrence of an internal pressure abnormality, the operation of the device is stopped, and the process is terminated. Therefore, if an abnormality occurs in the pressure of the inner chamber 2, the processing of steps S12 to S14 is not performed, and in this case, the image recording processing is prohibited. That is, since the rotating drum 1 is not driven, it is possible to prevent the printing plate S from scattering. Further, even when the diaphragm 20 ₈ of the inner pressure detector 20 for detecting the internal pressure becomes damaged, the compression coil spring 20
_{Since the} sensing plate 21 is urged outward by ₅ , it can be detected.

In this embodiment, in order to detect the internal pressure of the rotating drum, the displacement of the internal pressure detecting section composed of a diaphragm or the like is detected in a non-contact manner using a photo sensor. However, the present invention is not limited to this. Various modifications can be made without being performed. For example, a magnet may be provided in the sensing plate portion, and this may be detected by a magnetic sensor. In addition, since the rotating drum is driven to rotate, it is preferable that the internal pressure be detected in a non-contact manner. However, the present invention is not limited to the non-contact detection, and the displacement of the sensing plate is detected by a limit switch. You may.

[0030]

As is apparent from the above description, according to the present invention, based on the detection signal from the internal pressure detecting means, the second control means determines whether the internal pressure of the rotary drum is abnormal. be able to. As a result, when there is an abnormality, it is possible to prevent the photosensitive material from scattering by inhibiting the image recording process.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view illustrating a schematic configuration of a rotating drum portion of an image recording apparatus.

FIG. 2 is a cross-sectional view of a mechanism relating to detection of an internal pressure of a rotating drum.

FIG. 3 is a block diagram of a control device related to internal pressure detection.

FIG. 4 is a flowchart showing an internal pressure detection process.

[Explanation of symbols]

1 ... rotary drum 2 ... inner chamber 4 ... suction portion 5 ... main shaft 6 ... motor 10 ₂ ... check valve 11 ... blower pipe 12 ... Blower 20 ... pressure detection unit 30 ... photosensor 50 ... controller 51 ... Timer S ... plate

Claims (1)

(57) [Claims] 1. A rotating drum having an inner chamber and having an opening communicating with the inner chamber on the surface, wherein a photosensitive material is mounted on the surface at a position where the opening is installed, and A decompression means for decompressing the inner chamber via a pipe; a check valve provided in the middle of the pipe to maintain a decompressed state of the inner chamber; and a check valve mounted on the rotary drum while rotating the rotary drum. A recording unit that records an image on a photosensitive material; a first control unit that terminates decompression by the decompression unit; and after the decompression of the decompression unit is terminated by the first control unit, When a predetermined time has elapsed, an internal pressure detecting means for detecting the pressure of the inner chamber and generating a detection signal, and when the detection signal indicates that the internal pressure of the rotating drum exceeds a predetermined pressure, image recording by the recording means is performed. An image recording apparatus comprising: a second control unit for prohibiting the image recording apparatus.