JP2001246732A - Method and apparatus for printing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that for example, when many solid images are to be printed to cause the consumption of a large amount of ink, the sufficient supply of the ink to an ink fountain is often difficult, bringing insufficient density of the printed images. SOLUTION: When the ink is supplied to the ink fountain 27 by an ink pump 6 by the actuation of a pump motor 10 to be supplied to a printing drum 21, and when the ink is detected by an ink sensor 1, corresponding to the length of the operation time tEC of the motor 10 per unit time t, after the output of an ink detection signal from the sensor 1, the amount of the ink to be supplied to the printing drum 21 is changed. For the above process, a controller 30 for controlling the motor 10 is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a printing method and a printing apparatus, and more particularly, to an ink supply control method in a printing apparatus including a stencil printing apparatus and the like, and an ink supply control apparatus in the printing apparatus.

[0002]

2. Description of the Related Art A stencil printing method using a stencil printing apparatus has been known as a simpler printing method. this is,
A master perforated and made on the basis of image information is wound around the outer peripheral surface of a porous cylindrical printing drum also called a plate cylinder, and printing paper is pressed against the master on the printing drum by pressing means such as a press roller. Printing by supplying ink from the ink container to an ink reservoir provided inside the printing drum by driving an ink pump or the like, and supplying the ink from the ink reservoir to an ink supply member such as an ink roller. A print image is formed by passing ink from the opening portion of the drum and the punching portion of the master and transferring the ink to printing paper. An example of a configuration around the ink supply device for supplying ink to the printing drum of the stencil printing apparatus as described above will be described with reference to FIG.
When the presence / absence of ink to be supplied to the ink reservoir 27 is detected by the ink presence / absence detection sensor 1 for detecting the presence / absence of the ink to be supplied to the ink reservoir 27 by the amount of ink in the ink reservoir 27, the ink pump 6 and the ink presence / absence detection sensor 1, Drum 2
Generally, a pump motor 10 for driving the ink pump 6 to supply ink to the ink jet printer 1 is provided.

During printing or at the start of plate making before printing, as shown in FIG. 8, the ink presence / absence detection sensor 1 runs out of ink in an ink pool 27 via an ink detecting needle 2 (FIG. Is displayed), the pump motor 10 starts operating (in FIG. 8, it is displayed as “ON”), and the ink pump 6 is turned on.
Starts pumping, whereby ink is sucked and pumped out of the ink container 3 and sent out and supplied toward the inside of the printing drum 21, and the ink thus supplied is stored in the ink reservoir 27. When a predetermined amount of ink is accumulated in the ink reservoir 27, the presence / absence of ink in the ink reservoir 27 is detected by the ink presence / absence detection sensor 1 via the ink detection needle 2, and an ink presence signal from the ink presence / absence detection sensor 1 (in FIG. 8, The pump motor 10 always stops its operation at a fixed timing after a fixed ink replenishment confirmation time tα has elapsed from immediately after the output (displayed as “present”) (displayed as “OFF” in FIG. 8). As a result, the pumping of the ink pump 6 has been stopped.

Stopping the operation of the pump motor 10 after a lapse of a fixed ink supply determination time tα immediately after the output of the ink presence signal from the ink presence / absence detection sensor 1 can be said to secure design margin. That is, normally, a capacitance type is used as the ink detection needle 2 and the ink presence / absence detection sensor 1, and the detected capacitance changes depending on the amount of ink in the ink reservoir 27. This is based on the fact that the amount of ink to be replenished to 27 is determined in advance with a design margin. In FIG. 8, reference symbol tAn denotes an ink absence detection time in an arbitrary time zone, and tCn denotes an operation time of the pump motor 10 (pumping drive time of the ink pump 6) in an arbitrary time zone. The symbol tBn represents an ink presence detection time in an arbitrary time zone, and the symbol tBn-1 represents an ink presence detection time immediately before the ink presence detection time tBn in an arbitrary time zone.

[0005]

However, for example, when there are many solid images as print images and the consumption of ink is intense, the replenishment and supply of ink to the ink reservoir 27 may not be in time. ,
There is a problem that the print image density is reduced.
Contrary to the above, for example, when the printing rate is low and the consumption of ink is small, the pump motor 10 is operated in vain even though the supply and supply of the ink to the ink reservoir 27 are sufficient. Therefore, there is a problem that power is wasted.

Therefore, the present invention can always supply an appropriate amount of ink to the printing drum regardless of the ink supply conditions that affect the supply of ink to the printing drum, and can always achieve good printing. It is an object of the present invention to provide a novel printing method and a new printing apparatus that can achieve image density and save energy (hereinafter, referred to as “energy saving”).

[0007]

In order to achieve the above-mentioned object, the present invention is characterized by adopting the following constitution in the invention of each claim. Claim 1
In the invention described in the above, when the absence of ink is detected by the ink presence / absence detection means for detecting the presence / absence of ink to be supplied to the printing drum, the operation of the pump driving means for driving the ink pump to supply ink to the printing drum is performed. In the printing method for supplying ink to the printing drum, when the ink pump is supplying ink to the printing drum by the operation of the pump driving unit, the presence of ink is detected by the ink presence / absence detecting unit. Changing the amount of ink supplied to the printing drum after the ink detection means detects the presence of ink, according to the length of operation time per unit time of the pump driving means. And

According to a second aspect of the present invention, in the printing method according to the first aspect, the operation of the pump driving means causes
When pumping the ink pump, the length of the entire driving time during the pumping is automatically changed.

According to a third aspect of the present invention, in the printing method of the first aspect, the operation of the pump driving means causes
When the ink pump is pumped, a cycle between the pumps is automatically changed.

According to a fourth aspect of the present invention, in the printing method of the first aspect, the operating speed of the pump driving means is automatically changed.

According to a fifth aspect of the present invention, there is provided a printing method for supplying ink to the printing drum by operating a pump driving means for driving an ink pump to supply the ink to the printing drum. By the ink supply amount setting means for changing the supply amount,
The ink supply amount is manually changed.

According to a sixth aspect of the present invention, there is provided an ink presence / absence detection means for detecting the presence / absence of ink to be supplied to a printing drum, an ink pump for supplying ink to the printing drum, and the absence of ink detected by the ink presence / absence detection means. When done
In a printing apparatus comprising: a pump driving unit that drives the ink pump to supply ink to the printing drum, when the ink pump is supplying ink to the printing drum by operating the pump driving unit. The printing drum after outputting the ink presence signal from the ink detection means in accordance with the length of operation time per unit time of the pump driving means when the presence of ink is detected by the ink presence / absence detection means. And a control means for controlling the pump driving means so as to change the amount of ink supplied to the pump.

According to a seventh aspect of the present invention, in the printing apparatus according to the sixth aspect, when the ink pump is pumped by the operation of the pump driving means, the control means determines that the ink pump performs the pumping. The pump driving means is controlled so as to automatically change the length of the entire driving time during the operation.

According to an eighth aspect of the present invention, in the printing apparatus according to the sixth aspect, when the ink pump is pumped by the operation of the pump driving means, the control means determines a cycle between the pumping by the ink pump. The pump driving means is controlled so as to change automatically.

According to a ninth aspect of the present invention, in the printing apparatus according to the sixth aspect, the pump driving means is a pump driving motor having a variable rotation speed, and the control means automatically changes the rotation speed. The pump drive motor is controlled so as to cause the pump drive motor to rotate.

According to a tenth aspect of the present invention, there is provided a printing apparatus comprising: an ink pump for supplying ink to a printing drum; and pump driving means for driving the ink pump to supply ink to the printing drum. Ink supply amount setting means for changing the ink supply amount to be supplied to the drum; and control for controlling the pump driving means so as to change the ink supply amount according to an output signal from the ink supply amount setting means. Means.

According to an eleventh aspect of the present invention, in the printing apparatus according to the tenth aspect, the ink supply amount setting means is provided on an operation panel.

[0018] The invention according to claim 12 is based on claims 6, 7, and
10. The printing apparatus according to claim 8 or 9, wherein the ink supply amount setting means for changing the ink supply amount, and the pump so as to change the ink supply amount according to an output signal from the ink supply amount setting means. Controlling the driving unit, the control unit is different from the control unit, the another control unit is only when receiving the output signal from the ink supply amount setting unit, the pump drive by the control unit The pump driving means is controlled so as to change the ink supply amount prior to the control operation of the means.

Here, the "ink presence / absence detecting means for detecting the presence / absence of ink to be supplied to the printing drum" in claims 1 and 6 and the like includes, in addition to the ink presence / absence detecting means as stated, the ink supply to the printing drum. Also included is an ink amount detecting means for detecting the amount of ink to be applied. This is because the ink amount detecting means also detects the amount of ink, and finally detects the presence or absence of ink to be supplied to the printing drum.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention including embodiments with reference to the drawings (hereinafter, simply referred to as "embodiments").
Will be described. Components (members and components) having the same function, shape, and the like in the above-described conventional example and each embodiment are denoted by the same reference numerals, and description thereof will be omitted as much as possible. In the drawings, components that are configured as a pair and do not need to be specifically distinguished and described will be replaced with the description by appropriately describing one of them in order to simplify the description. For the sake of simplicity of the drawings and the description, components that do not need to be particularly described in the drawings may be omitted without omission, even if they are components to be shown in the drawings.

First, the overall configuration and operation of a digital thermosensitive stencil printing apparatus to which the present embodiment is applied will be described with reference to FIG. Reference numeral 50 indicates an apparatus body frame. A portion indicated by reference numeral 80 on the upper part of the apparatus main body frame 50 constitutes a document reading unit, a portion indicated by reference numeral 90 below the plate reading plate feeding portion, and a portion indicated by reference numeral 20 on the left side thereof includes a printing drum 21 and the like. The arranged printing drum portion, a portion indicated by reference numeral 70 on the left side thereof is a plate discharging unit, a portion indicated by reference numeral 110 below the plate making and feeding unit 90 is a paper feeding unit, and a portion indicated by reference numeral 120 below the printing drum 21 is indicated by a mark. The portion indicated by reference numeral 130 at the lower left of the pressure unit and the apparatus main body frame 50 indicates a paper discharge unit.

Next, the operation of the thermosensitive stencil printing apparatus will be described below, including its detailed configuration. First, a document table (not shown) arranged above document reading section 80
Then, a document 60 having an image to be printed is placed thereon, and the plate making start key 41 of the operation panel 40 shown in FIG. This prepress start key 4
With the pressing of 1, the plate discharging process is performed first. That is, in this state, the used heat-sensitive stencil master 61b (hereinafter, “used master 61b”) used in the previous printing is provided on the outer peripheral surface of the printing drum 21 of the printing drum unit 20.
Remains attached.

First, the printing drum 21 rotates counterclockwise, and the used master 61b on the outer peripheral surface of the printing drum 21 is rotated.
The rear end portion of the plate discharge roller pair 71 in the plate discharge section 70
a, 71b, the pair of rollers 71a, 71b rotates while scooping up the rear end of the used master 61b with one of the plate discharge rollers 71a.
a, 71b, a plate discharging roller pair 73a, 73 disposed to the left of
b is discharged into the plate discharge box 74 while being conveyed in the direction of arrow Y1 by the plate discharge transfer belt pairs 72a, 72b stretched between the plate discharge separation roller pairs 71a, 71b. The plate is peeled off from the surface and the plate discharging process is completed. At this time, the printing drum 21 continues to rotate counterclockwise. The used master 61b that has been peeled and discharged is thereafter compressed inside the plate discharge box 74 by the compression plate 75.

In parallel with the plate discharging process, the original reading section 80 reads the original. That is, the document 60 placed on the document table (not shown) is separated from the separation roller 81, the pair of front document conveyance rollers 82 a and 82 b, and the pair of rear document conveyance rollers 83.
Each of the rotations a and 83b is used for exposure reading while being conveyed in the directions of arrows Y2 to Y3. At this time,
When there are many originals 60, only the lowermost original is conveyed by the action of the separation blade 84. The image reading of the original 60 is performed while being conveyed on the contact glass 85.
The reflected light from the surface of the original 60 illuminated by the fluorescent lamp 86 is reflected by a mirror 87 and passed through a lens 88 to be reflected by the CC.
This is performed by causing the light to enter an image sensor 89 made of D (charge coupled device) or the like. That is, the reading of the document 60 is performed by a known “reduced document reading method”, and the document 60 from which the image has been read is discharged onto the document tray 80A. The electric signal photoelectrically converted by the image sensor 89 is input to an analog / digital (A / D) conversion board (not shown) in the apparatus body frame 50 and is converted into a digital image signal.

On the other hand, in parallel with this image reading operation,
A plate making and plate feeding process is performed based on the digitalized image information. That is, the heat-sensitive stencil master 61 (hereinafter, referred to as “master 61”) set at a predetermined portion of the plate making and feeding unit 90 is pulled out from a rolled state in a roll shape, and is transferred to the thermal head 91 via the master 61 via the master 61. Due to the rotation of the platen roller 92 and the pair of feed rollers 93a and 93b, which are pressed, the sheet is intermittently conveyed to the downstream side of the conveying path. With respect to the master 61 conveyed in this way, a large number of minute heating elements arranged in a line in the main scanning direction of the thermal head 91 correspond to digital image signals sent from the A / D conversion board. The thermoplastic resin film portions of the master 61 that selectively generate heat and are in contact with the heat-generating heating elements are melt-punched. in this way,
The image information is written as a punching pattern by the position-selective fusion punching of the master 61 according to the image information. The leading end of the prepressed master 61a on which the image information is written is
The printing drum 21 is fed toward the outer peripheral side of the printing drum 21 by the pair of plate feeding rollers 94a and 94b, and its traveling direction is changed downward by a guide member (not shown). 22 hangs down (shown by phantom lines). At this time, the printing drum 2
In No. 1, the used master 61b has already been removed by the plate discharging process.

Then, the leading end of the prepressed master 61a is
When the printing drum 21 is clamped by the clamper 22 at a constant timing, the printing drum 21 gradually winds the stencil master 61a around the outer peripheral surface while rotating in the direction of the arrow (clockwise) in the figure. The rear end of the master 61a is cut to a predetermined length by the cutter 95 after the completion of the master making. When one master plate master 61a is wound around the outer peripheral surface of the printing drum 21, the master making and plate feeding steps are completed, and the printing step is started. First, the printing paper 6 loaded on the paper feed table 51
2, the uppermost one of the registration rollers 113 is fed by the feed roller 111 and the separation roller pairs 112a and 112b.
a in the direction of arrow Y4 toward the printing pressure unit 12 at a predetermined timing synchronized with the rotation of the printing drum 21 by the pair of registration rollers 113a and 113b.
Sent to 0. When the sent printing paper 62 comes between the printing drum 21 and the press roller 23, the press roller 23, which has been separated below the outer peripheral surface of the printing drum 21, is moved upward, so that the printing drum 21 The master 61a is pressed by the plate-making master 61a wound on the outer peripheral surface. Thus, the opening portion of the printing drum 21 and the master
Ink oozes out from the perforated portion 1a (both are not shown), and the ooze out ink is transferred to the surface of the printing paper 62 to form a print image.

At this time, on the inner peripheral side of the printing drum 21,
A plurality of ink supply holes 24 formed in the ink supply pipe 24
a, ink is supplied dropwise to an ink reservoir 27 formed between the ink roller 25 and the doctor roller 26, and is supplied in the same direction as the rotation direction of the printing drum 21 and in synchronization with the rotation speed of the printing drum 21. The ink is supplied to the inner peripheral side of the printing drum 21 by the ink roller 25 which is in contact with the inner peripheral surface while rotating. In addition, as ink,
For example, W / O emulsion inks are preferably used, but are not limited thereto.

The printing paper 62 on which the print image is formed in the printing pressure unit 120 is discharged from the paper discharge peeling claw 1 in the paper discharge unit 130.
14, the conveyor belt 117 stretched around the suction / discharge entrance roller 115 and the suction / discharge exit roller 116 while being sucked by the suction fan 118 and rotated in the counterclockwise direction. Is transported toward the downstream side of the paper discharge unit 130 as shown in FIG.
2 are sequentially discharged and loaded. In this way, the so-called test printing (also called plate printing) is completed.
Next, referring to FIG. 4, if the number of prints is set using the numeric keypad 43 of the operation panel 40 shown in FIG. 4 and the print start key 42 shown in FIG. In the process, each process of paper feeding, printing, and paper discharging is repeatedly performed for the set number of prints, and all the processes of stencil printing are completed. (Embodiment 1) Referring to FIG. 1, FIG. 2 and FIG.
(Hereinafter, referred to as “Embodiment 1”) will be described. First, referring to FIG. 1, the configuration around the printing drum unit 20 will be supplementarily described, and an ink supply device 29 for supplying ink to the printing drum 21 and an ink supply control device for controlling the ink supply will be described. Will be described in detail.

As described above, the printing drum section 20 includes a printing drum 21 for winding the master plate 61a made and transported by the plate making and feeding section 90 around its outer peripheral surface.
An openable and closable clamper 22 extending in the axial direction on a part of the outer peripheral surface of the printing drum 21 to sandwich the leading end of the plate-making master 61a, while rotating in the same direction as the rotation direction of the printing drum 21. An ink roller 25 that supplies ink to the inner peripheral surface of the printing drum 21, and a doctor roller that is arranged in parallel with the ink roller 25 with a small gap therebetween and forms an ink pool 27 having a wedge-shaped cross section between the ink roller 25 and the ink roller 25. 26 and an ink supply pipe 24 for supplying ink to the ink reservoir 27. In the vicinity of the outer peripheral surface of the printing drum 21 facing the ink roller 25, a press roller 23 that swings up and down to press the printing paper 62 against the printing drum 21
Is arranged.

The printing drum 21 has a well-known porous cylindrical shape and is rotatably supported around a drum shaft 24 also serving as an ink supply pipe 24. The printing drum 21 is provided to extend in the central axis direction of the ink supply pipe 24,
A metal supporting cylinder having a large number of fine openings 21a having a printing ink passage property, and a metal wrapped around the outer peripheral surface of the supporting cylinder, holding and diffusing ink on the outer peripheral surface;
It has a two-layer structure with a porous elastic layer (a resin or metal mesh screen layer (not shown)) as a layer that ejects ink by pressing. In the supporting cylinder,
A printable area in which the opening 21a is formed over a predetermined range on the circumference except for the periphery of the clamper 22, and a non-printing non-printable area in which the opening 21a is not formed are formed. ing. Non-printing areas are also provided on both side edges of the support cylinder. The printing drum 21
For example, FIGS. 2 and 3 of JP-A-5-229243.
Are unitized similarly to the plate cylinder device 55 shown in FIG. Through this drum unit, the printing drum 21 is detachable from the apparatus body frame 50 shown in FIG. Attaching and detaching means similar to the holding means 36 shown in FIG. 2 of JP-A-5-229243 is provided on the apparatus body frame 50 side, and the printing drum 21 mounted on the apparatus body frame 50 is provided. Is detachably held. The printing drum 21 is driven to rotate clockwise and counterclockwise by a main motor (not shown).

The ink supply pipe 24 is provided in accordance with the above-mentioned JP-A-5-22.
As shown in FIG. 2 of Japanese Patent No. 9243, both ends are inserted into insertion holes formed in a front frame and a rear frame (both not shown), and are screwed using a fixing tool (not shown). For example, it is fixed to the front frame and the rear frame.

The ink roller 25 is made of metal such as aluminum or stainless steel, rubber, or the like, and rotates clockwise with the print drum 25 by a gear train (not shown). The doctor roller 26 is formed of metal such as iron or stainless steel, and rotates counterclockwise by a gear train (not shown). The ink roller 25 and the doctor roller 26 are rotatably supported by an ink side plate (not shown) which is vertically provided to the ink supply pipe 24.

The ink supply device 29 includes the ink roller 25, the doctor roller 26, and the ink supply pipe 2 described above.
4 has a piston rod 8 and a base 7 which can reciprocate in the direction shown by the arrow in the figure with respect to the main body thereof. Pump 6, which feeds the ink, the ink supply pipe 9 for inserting and connecting the ink pump 6 and the ink supply pipe 24, and the ink pump 6 which is detachably provided on the ink container holder 4. An ink container 3 having a base 5 which is detachable from the
And a pump motor 10 having a disk 11 attached and fixed to its output shaft and reciprocating the piston rod 8 of the ink pump 6 via a link 12 connected to the disk 11 in a manner to be described later. And the link 12 that connects the disk 11 and the disk 11 in a manner described later. FIG. 1 shows the configuration around the ink supply device 29 in a somewhat enlarged and exaggerated manner. Ink supply tube 9, ink pump 6, ink container holder 4, ink container 3, link 12, and pump motor 10 constituting ink supply device 29
The gripping frame, the rear frame, and the front frame (both not shown) are attached and fixed in the up-down direction of the ink supply pipe 24 on the near side of the paper surface of FIG. Are provided on the front frame side.

The ink pump 6 is a reciprocating pump, and the piston rod 8 reciprocates in the vertical direction indicated by the arrow in the drawing, thereby sucking and pumping out the ink in the ink container 3 and passing through the ink supply pipe 9. It is configured to send out ink to the ink supply pipe 24. Ink pump 6
The piston rod 8 has a link 12 whose one end is pivotally connected to the front frame via a shaft 13.
It is swingably supported at a predetermined angle via a. The output shaft of the pump motor 10 is fixed to the center of rotation of the disk 11, and a pin 11a is implanted at a position offset from the center of rotation of the disk 11 to the outside. On the other hand, link 1
On the other end side of 2, a long hole 12b is formed, and the pin 11a of the disk 11 is loosely fitted in the long hole 12b, and the pin 11a is slidable within the formation range of the long hole 12b. It has been made.

The pump motor 10 is a DC motor. An electrical connector (not shown) for electrically connecting and coupling to the input side of the pump motor 10 is attached to an outer surface of the rear frame. Device body frame 5
On the 0 side, an electric connector for supplying and controlling electric power for operating the pump motor 10 by being opposed to and engaging with the electric connector is attached. In the first embodiment, a description will be given assuming that the pump motor 10 operates at a constant rotation speed and at a constant cycle between pumping operations by the ink pump 6.

Accordingly, when the pump motor 10 is turned on and rotated, the disc 11 and the pin 11a are rotated, and this rotational motion is converted into a swinging motion of the link 12,
Further, the swinging motion of the link 12 is converted into a vertical reciprocating motion of the piston rod 8 as indicated by an arrow in the drawing, whereby the ink in the ink container 3 is sucked and drawn out, and the ink supply pipe 9 and the ink supply The ink is sent to the pipe 24 and supplied to and supplied to the ink reservoir 27.

Next, the configuration around the ink supply control device will be described. The ink supply control device according to the first embodiment detects an ink presence / absence sensor 1 as an ink presence / absence detection unit that detects the presence / absence of ink to be supplied to the inner peripheral surface of the printing drum 21 by detecting the amount of ink in the ink pool 27.
And a pumping number sensor 14 as a pumping number detecting means for detecting the pumping number of the ink pump 6.
And a control unit 30 provided on the apparatus body frame 50 side and controlling the pump motor 10 to drive the ink pump 6 in accordance with each output signal from the ink presence / absence detection sensor 1 and the pumping frequency sensor 14 as described later. It is mainly composed of

The ink presence / absence detection sensor 1 is fixedly mounted on the upper portion of the rear frame provided on the back side of the paper in FIG. On the input side of the ink presence / absence detection sensor 1, an ink detection needle 2 for detecting the amount of ink in the ink reservoir 27 in a capacitive manner is electrically connected. 2 shall be included. The ink presence / absence detection sensor 1 has the same configuration as the ink sensor 54 disclosed in, for example, FIG. 1 of JP-A-5-229243 described above. That is, the ink presence / absence detection sensor 1 includes a reference signal generation circuit (not shown) for generating a pulse signal at a predetermined pulse interval.
And a monostable circuit which is triggered by the falling (or rising) of the output pulse signal of the reference signal generating circuit and generates a pulse signal having a detection pulse width in response to the capacitance detected by the ink detecting needle 2. (Not shown), and a phase comparator (not shown) for comparing the phases of the output signals of the reference signal generating circuit and the monostable circuit and outputting a binary signal. Further, the ink presence / absence detection sensor 1 is disclosed in Japanese Patent Application Laid-Open No. H6-155885, FIG.
4 and the like are also preferably used.

The ink detecting needle 2 is held in an electrically insulating manner via a support plate (not shown) vertically provided at the center of the ink supply pipe 24. Detects the capacitance that changes according to the amount of ink. As disclosed in JP-A-6-155885 described above, the ink detecting needle 2 can increase the difference in the amount of change in the detection pulse width for the presence or absence of ink, thereby enabling stable detection. In order to improve the detection performance of the ink amount, two of the support plates are provided. Note that the ink presence / absence detection means is not limited to the ink presence / absence detection sensor 1, but includes a sensor that detects the presence or absence of ink by detecting a change in the transmission frequency due to a change in capacitance, or a photoelectric type. It may be.

The pumping number sensor 14 is a limit switch which detects the number of times of pumping of the ink pump 6 (the number of times of reciprocating movement is one) by operating in contact with the upper end of the reciprocating piston rod 8. It is fixed on the upper part of the rear frame. Note that the pumping frequency sensor 14 is not an essential component except for a case that is particularly described in an ink supply control operation described later, and may be removed from the block diagram of FIG.

An electrical connector (not shown) for electrically connecting and connecting each output side of the ink presence / absence detection sensor 1 and the pumping frequency sensor 14 to the control device 30 is attached to the outer surface of the rear frame. An electric connector which is opposed to and engages with the electric connector is mounted on the apparatus body frame 50 side.

The control device 30 includes a microcomputer, and includes a CPU (Central Processing Unit) 31 and an I / O
O (input / output) port (not shown), RAM capable of storing and holding a backup power supply (readable / writable storage device)
32, ROM (read only storage device) 33, timer 3
4 and the like, and are connected by a signal bus (not shown) or the like.

The CPU 31 of the control device 30 has a control function and a calculation / calculation function described later. The CPU 31 of the control device 30 (hereinafter, may be simply referred to as “control device 30” for simplicity of description) is connected to the ink presence / absence detection sensor 1 via the input port and the pair of electrical connectors. It is electrically connected to the frequency sensor 14 and receives each output signal from the ink presence / absence detection sensor 1 and the pumping frequency sensor 14. The control device 30 is electrically connected to the pump motor 10 via the output port, the pair of electric connectors, a motor drive circuit (not shown), and the like. 10 to control the operation of the pump motor 10.

The control device 30 operates when the ink pump 6 is supplying ink to the printing drum 21 by the operation of the pump motor 10, and when the ink presence sensor 1 detects the presence of ink in the ink reservoir 27. In accordance with the operation time of the pump motor 10 per unit time, the pump motor 10 is changed so that the ink supply amount to be supplied to the ink reservoir 27 after the output of the ink presence signal from the ink presence / absence detection sensor 1 is changed. It has a basic control function to control. In the basic control function described above, the control device 30 controls the pump motor 10 so as to automatically change the length of the entire drive time while the ink pump 6 performs pumping.
Has a first control function of controlling Here, the operating time per unit time of the pump motor 10 and the length of the entire driving time while the ink pump 6 is pumping, the ink pump 6 when the rotation speed of the pump motor 10 is not changed. The number of times of pumping is included. Therefore, in the first control function, the ink pump 6 operates the printing drum 2 by operating the pump motor 10 in the first control function.
When ink is supplied to the ink pump 6 and the presence or absence of ink in the ink reservoir 27 is detected by the ink presence / absence detection sensor 1, the presence or absence of ink depends on the number of times of pumping of the ink pump 6 per unit time. In other words, the pump motor 10 is controlled so that the number of times of pumping of the ink pump 6 after the output of the ink presence signal from the detection sensor 1 is automatically changed.
The RAM 32 temporarily stores the calculation / calculation results of the CPU 31, the ink presence / absence detection sensor 1, the pumping frequency sensor 14, or the operation panel 4 in an embodiment described later.
On / off signals and data signals input from various 0 keys are stored and stored as needed. ROM33
Is when the ink pump 6 is supplying ink to the printing drum 21 by the operation of the pump motor 10,
When the presence or absence of ink in the ink reservoir 27 is detected by the ink presence / absence detection sensor 1, the pump motor 10
The operation time per unit time of the pump motor 10 shifted in a direction to increase or decrease from the standard operation time per unit time (hereinafter, sometimes referred to as “standard time”) as a median value, and the ink presence / absence detection sensor 1 In order to always obtain a good print image density by appropriately changing the ink supply amount to be supplied to the ink reservoir 27 as the ink supply amount to be supplied to the print drum 21 after the output of the ink presence signal from Pump motor 1 for control
Data relating to 0 operation time is stored in advance. As the standard time, for example, under the standard environment and printing conditions, that is, the printing paper 6 of the printing paper size A3 conversion value at the normal printing speed conversion value of printing speed: 90 sheets / min.
In the printing conditions under which a proper print image density can always be obtained under the condition of printing hundreds of sheets 2 or more, the operating time per unit time of the pump motor 10 is set.

As described above, the relation data between the operation time per unit time of the pump motor 10 obtained by measuring the time including the standard time and the operation time of the pump motor 10 for controlling the pump motor 10 is, for example, It is set by conducting experiments. As the standard time, for example, the standard operation time per unit time of the pump motor 10 as described above may be set, or the standard number of times of pumping of the ink pump 6 may be set.

In FIG. 2, a timer 34 is provided with an operation time tEC (to be described later) per unit time tE of the pump motor 10.
In addition, the ink absence detection time tEA per unit time tE of the ink presence / absence detection sensor 1 and the unit time tE of the ink presence / absence detection sensor 1 are described later.
Per ink detection time tEB, pump motor 10
Operation stop time tED per unit time tE, ink absence detection time tAn in any time zone, ink presence detection time tBn in any time zone, operation time (or pumping drive time) tCn in any time zone, any It has a function of a timer means for counting the operation stop time (or pumping stop time) tDn or the like in the time zone.

Next, the operation relating to the ink supply control in the first embodiment will be described in detail. Before starting the description of the operation, the relationship between the ink pump 6 and the pump motor 10 and the reference numerals used in the timing charts of FIGS. 2 and 3 will be described. In each of the timing charts of FIGS. 2 and 3, the rising and falling relations of the on / off signals of the pump motor 10 and the ink pump 6 are represented ignoring a time delay in order to simplify the description of the control operation. ing. Therefore, pump motor 1
The on / off relationship between 0 and the ink pump 6 will be treated as equivalent hereinafter. For convenience of explanation, an example in which the pump motor 10 is controlled so as to automatically change the length of the entire driving time while the ink pump 6 performs pumping will be described first.

Symbols tA1, tA2,... TA5, tA6
Are the ink absence detection times during which the ink presence / absence detection sensor 1 detects the absence of ink, and are denoted by tB1, tB2,.
5, tB6 represent the ink presence detection time during which the ink presence / absence detection sensor 1 detects the presence of ink. Also, symbols tC1, tC2,... TC5, tC6
Are the operating time of the pump motor 10 or the pumping drive time during which the ink pump 6 is pumping by the operation of the pump motor 10, by the symbols tD1, tD2,.
5, tD6 is the time when the operation of the pump motor 10 is stopped or the operation of the pump motor 10 is stopped.
Represents the pumping stop time during which the pumping is stopped. Unit time tE of pump motor 10
Per operation time tEC (hereinafter simply referred to as “operation time tE
As an example, there is tEC = tC1 + tC2 + tC3 + tC4 + tC5 ′ shown in FIG.

As shown in FIG. 7, when the main motor is driven to rotate, the printing drum 21 mounted in the apparatus main body frame 50 is rotated clockwise and the ink roller 25 is rotated in the same direction. The printing process is performed while the ink in the ink pool 27 is supplied to the inner peripheral surface of the printing drum 21 by the rotation. When the predetermined printing process is performed as described above, the ink pool 2 gradually increases.
The ink 7 is consumed and decreased, and the ink detecting needle 2 does not contact the ink in the ink pool 27. Then, the capacitance detected by the ink detecting needle 2 decreases, and the pulse signal width output from the monostable circuit of the ink presence / absence detecting sensor 1 decreases, and accordingly, the output signal level of the phase comparing unit Is reduced (L level), the ink presence / absence detection sensor 1 detects that there is no ink, and sends an out-of-ink signal (indicated as “absent” in FIG. 2) to the control device 30 as shown in FIG. Send.

The control device 30 that has received the ink-out signal
As shown in FIG. 2, a command signal for turning on the pump motor 10 to drive the ink pump 6 is transmitted to the pump motor 10.
Send to As a result, the pump motor 10 starts operating and rotates, so that the piston rod 8 of the ink pump 6 reciprocates in the vertical direction indicated by the arrow in FIG. As a result, the ink in the ink container 3 is sucked and pumped out, sent out to the ink supply pipe 24 via the ink supply pipe 9, and the ink thus sent out is supplied to the ink supply hole 24.
The ink is dropped into the ink pool 27 from a, and supplied and supplied to the ink pool 27.

When the ink is replenished to the ink reservoir 27, the ink detecting needle 2 comes into contact with the ink in the ink reservoir 27 again, and the capacitance detected by the ink detecting needle 2 increases. The pulse signal width output from the circuit becomes longer, and the output signal level of the phase comparator rises (H level) accordingly, so that the ink presence / absence detection sensor 1 detects the presence of ink, and outputs an ink presence signal (FIG. 2).
Is displayed to the control device 30). At this time, as described with reference to FIG. 8, the control device 30 controls the pump motor so that the ink pump 6 is always pumped for a fixed ink supply determination time tα immediately after the output of the ink presence signal from the ink presence / absence detection sensor 1. 1
Therefore, the operation of the pump motor 10 is stopped (“OFF” in FIG. 2) after elapse of the pumping drive time of the ink pump 6: tC1 = tA1 + tα (however, the display of tα is omitted in FIG. 2). ), The pumping of the ink pump 6 is stopped.

Here, the symbol P indicates an ink presence / absence detection sensor 1 corresponding to the consumption / decrease of ink in the ink pool 27.
Represents one cycle of a series of ink supply operations from the detection of the absence of ink to the detection of the next absence of ink via the above-described operation.

Subsequently, as shown in FIG. 2, a series of ink supply operations similar to those described above are sequentially and repeatedly performed along with the execution of the printing process. In other words, the absence of ink is detected by the ink presence / absence detection sensor 1. The operation from P to the next detection of the absence of ink is performed repeatedly in one cycle P (in FIG. 2, the operation is performed for a total of five cycles P in FIG. 2), thereby supplying and replenishing ink to the ink reservoir 27. Stopping is repeated.

In FIG. 2, in addition to the first pumping drive time tC1, the subsequent pumping drive time tC1
Although the display of the ink replenishment confirmation time tα at 2,... TC5 is omitted, the ink replenishment confirmation time tα starts immediately after the output of the ink presence signal from the ink presence / absence detection sensor 1 as described with reference to FIG. It is always predetermined as a fixed time. That is, tC1 = tA1 + tα, t
C2 = tA2 + tα, tC3 = tA3 + tα, tC4 =
tA4 + tα, tC5 = tA5 + tα.

Here, for example, when the solid image is large and the ink consumption is extremely large as the print image, and the ink consumption is extremely large, for example, per unit time tE of the ink pump 6 under the standard environment and printing conditions described above. In comparison with the pumping drive state, the pump motor 10 is, of course, frequently driven by pumping. Therefore, attention is paid to such a phenomenon. Control. That is, FIG.
As a result of performing the ink supply / stop operation for a total of five cycles P, it is considered that a phenomenological sign that the pumping drive is frequently performed has already appeared in the ink supply / stop operation for a total of five cycles P, CPU 3 of control device 30
Under the control of 1, the timer 34 operates five times of the pump motor 10 included in the unit time tE: tC1, t
C2, tC3, tC4, tC5 'are measured, and the unit time tE is measured. First timed operating time tC
1 is stored in the RAM 32 as initial data. CPU
Reference numeral 31 denotes the operation time tC1 stored as initial data in the RAM 32 and the operation time t
A calculation for adding C2 is executed, and the calculation result is stored in RAM3.
2 is stored. Hereinafter, the same operation is sequentially performed, and C
The PU 31 has five operation times: tC1 and tC as the operation time tEC per unit time tE of the pump motor 10.
TEC = tC1 + tC2 + tC3 + tC4 + tC as an operating time obtained by adding 2, tC3, tC4, and tC5 ′.
Get 5 '. Then, the CPU 31 compares the total operation time tEC with the standard time while referring to the relation data in the ROM 33, and in this case, as described above, the operation time tEC
Since the EC is longer than the standard time, the operation time of the pump motor 10 corresponding to the operation time tEC longer than the standard time, that is, the ink supply amount to be supplied to the ink reservoir 27 is appropriately changed to always provide a good print image. Pump motor 1 for controlling pump motor 10 to obtain concentration
The operation time of 0 is obtained from the relational data in the ROM 33, and in order to increase the amount of ink supplied to the ink reservoir 27, after the ink presence signal is output from the ink presence / absence detection sensor 1, while the ink pump 6 is pumping. The pump motor 10 is controlled so that the entire driving time is longer than the standard time.

In other words, for example, when a large number of solid images are used as the print image and the consumption of ink is intense, and the amount of consumed ink is extremely large, the replenishment and supply of ink to the ink reservoir 27 may not be performed in time. From
In such a case, in the present embodiment, in the operation of the sixth period P, for example, a specific control operation shown in FIG. 3A is performed. The CPU 31 of the control device 30 refers to the relevant data in the ROM 33 as described above, and
(TEC = tC1 + tC2 + tC3 + tC4 + tC
5 ′) is compared with the standard time, and as shown in FIG.
The ink supply fixed time tα + tβ which is longer by β is stored in the ROM 33
The pumping drive time in the sixth cycle P longer than any pumping drive time up to the fifth cycle P: tC6 = tA6 + tα + tβ By controlling the pump motor 10 to automatically change the length of the driving time, the amount of ink supplied to the ink pool 27 after the output of the ink presence signal from the ink presence / absence detection sensor 1 is increased.

Thereafter, the standard time is set to be longer, and the next second operation time tEC ('tEC = tC6
+ TC7 + tC8 + tC9 + tC10 ') and the longer standard time, and by performing the same processing as in the first time, it is possible to control the ink supply amount with higher accuracy.

On the other hand, contrary to the above, for example, when the printing rate is low and ink consumption is small, the pumping drive state of the ink pump 6 per unit time tE under the standard environment and printing conditions described above. Since the pumping drive time is reduced as compared with the above, attention is paid to such a phenomenon, and the pump motor 10 is controlled as follows by accurately catching such a phenomenon sign. That is,
In FIG. 2, if the ink supply / stop operation for a total of five cycles P has been performed, a phenomenon sign that the pumping drive time has decreased has already appeared in the ink supply / stop operation for a total of five cycles P. Under the control of the CPU 31 of the control device 30, the CPU 31 operates the pump motor 10 in the same manner as described above and operates the pump motor 10 for an operating time tEC per unit time tE.
Each operation time of five times: tC1, tC2, tC3
tEC = tEC = tC5 ′
tC1 + tC2 + tC3 + tC4 + tC5 ′ are obtained. Then, the CPU 31 compares the total operation time tEC with the standard time while referring to the relation data in the ROM 33. In this case, since the operation time tEC is shorter than the standard time as described above, the operation time tEC is shorter than the standard time. Operating time tE
The operation time of the pump motor 10 corresponding to C, that is, power is not wasted, and the amount of ink supplied to the ink reservoir 27 is appropriately changed to always obtain a good print image density. The operation time of the pump motor 10 for controlling the pump 10 is obtained from the related data in the ROM 33, and after the output of the ink presence signal from the ink presence / absence detection sensor 1, the ink pump 6 controls the pump motor 10 so that the total drive time during pumping is shorter than the standard time.

In other words, for example, when the printing rate is low and ink consumption is low, the pump motor 10 is operated unnecessarily even though the supply and supply of ink to the ink reservoir 27 are sufficient. In such a case, in this case, in the operation of the sixth period P, for example, a specific control operation shown in FIG. 3B is performed. That is, the CPU 31 of the control device 30
Refers to the operation time tEC (tEC = tC1 + tC2 + tC) while referring to the related data in the ROM 33 as described above.
3 + tC4 + tC5 ′) and the standard time, and FIG.
As shown in (b), the ink replenishment confirmation time tα shorter than the ink replenishment confirmation time tα up to the fifth cycle P by the time tγ.
-Tγ is obtained by referring to the relation data in the ROM 33,
Pumping drive time in the sixth cycle P shorter than any pumping drive time up to the fifth cycle P: tC6 = tA6 + t
By controlling the pump motor 10 to automatically change the length of the entire driving time during pumping by the amount corresponding to α-tγ, the ink presence signal from the ink presence / absence detection sensor 1 is provided. That is, the amount of ink supplied to the ink pool 27 after output is reduced.

Thereafter, the standard time is reset to be shorter, and the second operation time tEC ('tEC = tC6
+ TC7 + tC8 + tC9 + tC10 ') and the shortened standard time, and by performing the same processing as in the first time, more accurate ink supply amount control becomes possible.

In the first embodiment, the pumping frequency sensor 14 shown in FIG. 1 is not an essential control structure, and need not be provided.
A method for controlling the amount of ink supplied to the printer will be described.

In this system, the number of times of pumping of the ink pump 6 corresponding to the standard time is previously stored in the ROM 33 instead of the standard time previously stored in the ROM 33 in the first embodiment. Being performed, and the control device 30 includes, in the first control function,
The unit time of the ink pump 6 when the ink pump 6 is supplying ink to the printing drum 21 by the operation of the pump motor 10 and when the ink presence sensor 1 detects the presence of ink in the ink pool 27. The main difference is that the pump motor 10 is controlled so that the number of times of pumping of the ink pump 6 after the output of the ink presence signal from the ink presence / absence detection sensor 1 is automatically changed according to the number of times of pumping per tE. I do.

In this method, unless the operating conditions such as the rotation speed of the pump motor 10 are changed, the R
The standard time stored in advance in the OM 33, the number of times of pumping of the ink pump 6 corresponding to the standard time previously stored in the ROM 33 in this method, the operation time tEC in the first embodiment, and the ink pump in this method The number of times of pumping per unit time tE of 6 can be regarded as equivalent and belongs to obvious technical matters, and can be easily implemented.

As described above, in the first embodiment, when the ink pump 6 supplies ink to the printing drum 21 by the operation of the pump motor 10, the ink in the ink pool 27 is detected by the ink presence / absence detection sensor 1. According to the length of operation time tEC per unit time tE of the pump motor 10 when the presence is detected, the amount of ink supplied to the ink reservoir 27 after the output of the ink presence signal from the ink presence / absence detection sensor 1 is determined. It can be said that a printing method in which the amount of ink supplied to the printing drum 21 is changed by changing the printing method is used. Also,
More specifically, in the printing method described above,
When the ink pump 6 is pumped by the operation of the pump motor 10, it can be said that a printing method in which the length of the entire drive time during the pumping of the ink pump 6 is automatically changed has been used.

As is clear from the timing chart of FIG. 2, the control object quantity compared with the standard time by the control device 30 is, as a first example, the operation time tEC (tEC = tEC = tE) of the pump motor 10 per unit time tE. tC1
+ TC2 + tC3 + tC4 + tC5 '), and when the unit time tE is represented by the same scale in FIG. 2, the following various total times are equivalent, and these can be used.

As a second example, the operation stop time tD1, tD2,... TD5 of the pump motor 10 is used.
tD4 + tD5. In this case, the operation stop time tED
Is shorter than the standard time, the control device 30 controls the pump motor 10 so as to increase the amount of ink supplied to the ink pool 27 after the output of the ink presence signal from the ink presence / absence detection sensor 1. Conversely, when the operation stop time tED is longer than the standard time, the pump motor 10 may be controlled so as to decrease the ink supply amount.

As a third example, an ink presence / absence detection sensor 1
No ink is detected when no ink is detected: tA
, TA2,..., TA5, and the ink absence detection time tEA per unit time tE of the ink presence / absence detection sensor 1 is tEA = tA1 + tA2 + tA3 + t
A4 + tA5. In this case, the ink out detection time t
When EA is longer than the standard time, the control device 30 controls the pump motor 10 so as to increase the amount of ink supplied to the ink reservoir 27 after the output of the ink presence signal from the ink presence / absence detection sensor 1. Conversely, when the absence-of-ink detection time tEA is shorter than the standard time, the pump motor 10 may be controlled so as to reduce the ink supply amount.

As a fourth example, an ink presence / absence detection sensor 1
Is detecting the presence of ink Ink presence detection time: tB
, TB2,... TB5 are used, and the ink presence detection time tEB of the ink presence / absence detection sensor 1 per unit time tE is tEB = tB1 + tB2 + tB3 + t
B4 + tB5. In this case, the ink detection time t
When the EB is shorter than the standard time, the control device 30 controls the pump motor 10 so as to increase the amount of ink supplied to the ink pool 27 after the output of the ink presence signal from the ink presence / absence detection sensor 1. Conversely, when the ink detection time tEB is longer than the standard time, the pump motor 10 may be controlled so as to reduce the ink supply amount.

In the first to fourth examples described above, in the timing chart of FIG.
The number of prints to be printed during tB1, tB2,.
As a result of an experiment in which the number of printed sheets is counted from the detection of the presence of ink to the detection of absence of ink at normal temperature and normal humidity, a standard chart of printing paper size A3 is about 50 sheets. It turned out that it is effective when printing several hundred sheets or more, depending on whether it includes the time for the cycle.

The amount of control to be compared with the standard time by the control device 30 is not limited to the sum of various times as in the first to fourth examples described above, but may be an on / off signal of the pump motor 10. , Or the number of appearances of the ink presence / absence signal from the ink presence / absence detection sensor 1. In this case, in the timing chart of FIG.
Each of the number of occurrences of the OFF signal and the number of occurrences of the ink presence / absence signal from the ink presence / absence detection sensor 1 is 5
It was times.

Further, the control target quantity to be compared with the standard time by the control device 30 includes the sum of various times as in the above-described first to fourth examples, and the number of occurrences of the on / off signal of the pump motor 10. The present invention is not limited to the number of occurrences of the ink presence / ink absence signal from the ink presence / absence detection sensor 1 and may be the following. In other words, instead of the unit time tE, equivalent to this, the absence-of-ink detection time tAn in any time zone, the presence-of-ink detection time tBn in any time zone, the operation time tCn in any time zone, and any time zone By using each time corresponding to one cycle P of the operation stop time tDn, it can be used even in a printing condition for printing a smaller number of sheets. In this case, when the ink absence detection time tAn for one cycle P in an arbitrary time zone as the fifth example is longer than the standard time, the sixth example is performed.
When the ink presence detection time tBn for one cycle P in an arbitrary time zone as an example is shorter than the standard time, the operating time tCn of the pump motor 10 for one cycle P in an arbitrary time zone as a seventh example is standard. If the operation stop time tDn of the pump motor 10 for one cycle P in an arbitrary time zone as an eighth example is shorter than the standard time, the output of the ink presence signal from the ink presence / absence detection sensor 1 is performed. The pump motor 10 may be controlled so as to increase the amount of ink supplied to the ink reservoir 27 later. In the case opposite to the above, the pump motor 10 may be controlled so as to reduce the ink supply amount. The control target amount to be compared with the standard time by the control device 30 is not limited to the first example, but may be any of the second to eighth examples of the control target amount.

Therefore, according to the first embodiment, an appropriate amount of ink can always be supplied to the printing drum 21 irrespective of the ink supply conditions that affect the supply of ink to the printing drum 21. In addition, a good print image density can always be obtained, and energy saving can be achieved. Further, the function of the control device 30 as the control means can be performed without changing the conventional main device components (the ink presence / absence detection sensor 1, the ink pump 6, and the pump motor 10) and without adding components such as new sensors. The above advantage can be obtained only by a simple configuration of adding. (Modification 1 of Embodiment 1) Modification 1 of Embodiment 1 will be described. This modified example 1 is different from the configuration of the first embodiment in that the basic control function described above is provided instead of the control device 30 having the first control function in the first embodiment, and the pumping by the ink pump 6 is performed. The main difference is that a control device 30A having a second control function for controlling the pump motor 10 so as to automatically change the period between the two is provided.
In FIG. 1, only the control device is generally denoted by reference numeral 30 </ b> A to distinguish it from the overall configuration of the control device 30.

In the first modification, the pump motor 10 is not controlled so as to change the entire driving time while the ink pump 6 is performing the pumping as in the first embodiment. By making the operation of the motor 10 an intermittent operation at a certain timing, the same pumping driving time of the ink pump 6 is made the same, and the period between the pumping is automatically changed. That is, by continuously or intermittently operating the pump motor 10, in other words, by moving or stopping the pump motor 10 at a certain interval, the interval can be made longer than the operation of the pump motor 10 in the standard setting. The lower the ink supply, the shorter the interval (or the continuous operation), the higher the ink supply.

As described above, in the first modification, when the ink pump 6 is pumped by the operation of the pump motor 10, it can be said that the printing method of automatically changing the cycle between the pumping operations by the ink pump 6 is used. . In the first modification, the same advantages as those of the first embodiment can be obtained, and the above-mentioned advantages can be obtained only with a simple configuration in which the function of the control device 30A as the control unit is added. (Modification 2 of Embodiment 1) Modification 2 of Embodiment 1 will be described. The second modification is different from the configuration of the first embodiment in that a pump motor 10 having a variable rotation speed is used instead of the pump motor 10 having a constant rotation speed and the like. Control device 3 with functions
The main difference is that a control device 30B having the above-described basic control function and a third control function for controlling the pump motor 10 so as to automatically change the rotation speed is provided in place of the control device 30B. I do. In FIG. 1, only the control device is generally denoted by reference numeral 30 </ b> B to distinguish it from the entire configuration of the control device 30.

In the second modification, for example, the control device 30
B and the pump motor 10, a parallel input / output port LS
The rotational speed of the pump motor 10 composed of a DC motor is changed by interposing an I / D / A converter, an operational amplifier, a power amplifier circuit, and the like. In this way, it is possible to change the number of times of pumping of the ink pump 6 per unit time tE in FIG. Can be. It is needless to say that the second modification can be applied not only to the pump motor 10 composed of a DC motor but also to a case where another motor having a variable rotation speed, for example, a stepping (or pulse) motor is used.

From the above, it can be said that in the second modification, the printing method of automatically changing the rotation speed as the operating speed of the pump motor 10 was used. Modification 2
However, the same advantage as that of the first embodiment can be obtained, and the above-described advantage can be obtained only with a simple configuration in which the function of the control device 30B as the control unit is added. (Embodiment 2) Embodiment 2 will be described with reference to FIGS. 1, 4, 5, and 7. FIG. The second embodiment is different from the configuration of the first embodiment in FIG. 4 in which an ink supply amount adjusting key group 44 as an ink supply amount setting unit for changing the amount of ink supplied to the ink reservoir 27 is provided. Having the operation panel 40 shown in the drawing, and controlling the pump motor 10 to change the ink supply amount in accordance with an output signal from the ink supply amount adjustment key group 44 instead of the control device 30 of the first embodiment. The main difference lies in having a control device 30C shown in FIG. 5 as a means.

The operation panel 40 is provided above the original reading section 80 shown in FIG. Operation panel 40
As shown in FIG. 4, a plate making start key 4 for starting a series of steps (operations) from reading of a document image to plate discharging, plate making, plate feeding, plate printing, and sheet discharging step.
1 and ten keys 43 for setting and inputting the number of prints and the like
A print start key 42 for activating a printing operation for the number of prints set / input with the ten keys 43;
An LCD for displaying an operation state and a message for adjusting an ink supply amount to be supplied to the ink reservoir 27, a display of a selected function, and the like, and displaying an operation content for selecting and setting the function as needed. (Liquid crystal display)
The display unit 49 and the four displays (“←”, “→”, “cancel”, and “setting”) displayed within the rectangular section at the bottom of the LCD display unit 49 respectively correspond to them. And an ink supply amount adjustment key group 44 composed of four keys set at the lower part of the table.

The LCD display section 49 is driven via a liquid crystal drive circuit (not shown) and is controlled by the control device 30C via the liquid crystal drive circuit. The ink supply amount adjustment key group 44 corresponds to a left arrow shift key 45 for shifting leftward to select an ink supply amount corresponding to “←” in order from the left in FIG. Right arrow shift key 46 for shifting rightward to select the ink supply amount, and a cancel key 47 for canceling the ink supply amount once set corresponding to "cancel".
And a setting key 48 for setting the ink supply amount selected by the left arrow shift key 45 or the right arrow shift key 46 corresponding to the “setting”.

In the second embodiment, as shown in the LCD display section 49, the ink supply amounts are “low”, “slightly low”, “standard”, “slightly high”, and “highly” in order from the left. Any one of the five steps can be selected by operating the ink supply amount adjustment key group 44. After the power switch (not shown) of the apparatus is turned on, the “standard” is normally set to “standard”. It is automatically selected and set in reverse video. For example, in the case of selecting and setting "many" as the ink supply amount, pressing the right arrow shift key 46 cancels the black-and-white inverted display of "standard", shifts to "many", selects the "many", and then selects the setting key 48 By pressing, "many" is displayed in black and white inverted and input / set.

The CPU 31 of the control device 30C (hereinafter, may be simply referred to as “control device 30C” for the sake of simplicity of description) has the same connection relationship on the input side as in the first embodiment, and further includes the input port and the like. Are electrically connected to the respective keys 45 to 48 of the ink supply amount adjusting key group 44 on the operation panel 40, and receive respective output signals from the keys. The control device 30C has the same connection relation on the output side as in the first embodiment, and is electrically connected to the LCD display unit 49 via the output port and the liquid crystal drive circuit and the like. A command signal for controlling 49 is transmitted to the LCD display unit 49.

Next, the operation of the second embodiment will be described.
For example, there are many solid images as print images, and depending on the position of the solid images, before the ink presence / absence detection sensor 1 detects absence of ink in the ink pool 27 as in the first embodiment, the ink pool in the width direction of the print drum 21 is detected. 27
Is partially consumed, causing a problem that the print image density locally decreases. In such a case, the above problem cannot be solved by the ink supply control system as in the first embodiment.

Therefore, for example, when the user checks the print image of the printing paper on which the printing is first performed and prints, and finds that there are many solid images and the positions of the solid images are unevenly distributed, Before starting normal printing, the user performs the key operation of the ink supply amount adjustment key group 44 as in the above-described example, so that the control device 30C can be operated before the ink in the ink pool 27 is partially consumed. Controls the pump motor 10 so as to increase the amount of ink supplied to the ink reservoir 27 in response to an output signal from the ink supply amount adjusting key group 44. Therefore, the user manually controls the ink in the ink reservoir 27 in advance. The amount can be increased, and the problem described above can be solved.

Contrary to the above, for example, when the printing rate is low and the consumption of ink is small, the pump motor 10 is operated even though the supply and supply of the ink to the ink pool 27 are sufficient. In such a case, the user operates the ink supply amount adjustment key group 44 to operate the ink supply amount adjustment key group 44 to select and set, for example, “reduced”, in contrast to the above-described example. By doing so, before the ink presence / absence detection sensor 1 detects the absence of ink in the ink pool 27 as in the first embodiment, the control device 30C responds to the output signal from the ink supply amount adjustment key group 44 according to the output signal.
Since the pump motor 10 is controlled so as to reduce the amount of ink supplied to the ink pool 27, the amount of ink in the ink pool 27 can be appropriately adjusted in advance by a user's manual operation.

The ink supply amount setting means for changing the ink supply amount is not limited to the one provided with the ink supply amount adjustment key group 44, but may be, for example, an LCD shown in FIG.
The system shown in the display unit 49A may be used. In this method, the ink supply amount is divided into ten stages of 1 (small) to 10 (many), and each stage value is selected by the ten keys 43 shown in FIG. 4 and then directly set by the setting key 48 shown in FIG. Is set. Supply amount shown in FIG. 6: 5
Indicates that the standard ink supply amount is selected and set.

In the second embodiment and the above-mentioned example, since the versatile menu screen method is employed for performing various job processes, as described above, the operation involves a little complicated operation. When the screen method is not used, the ink supply amount selection key corresponding to the ink supply amount to be selected and set, or a single key that can be selected and set by sequentially switching the ink supply amount each time the button is pressed. Of course, it doesn't matter.

As described above, in the second embodiment and the like,
It can be said that a printing method in which the ink supply amount is manually changed by the ink supply amount setting means for changing the ink supply amount supplied to the printing drum has been used. According to the second embodiment, it is possible to supply a desired amount of ink to the print drum at the discretion of the user, regardless of the ink supply conditions that affect the supply of ink to the print drum. The print image density can be obtained, and energy saving can be achieved.

The embodiment of the present invention is not limited to the above-described one. For example, the control device 30C and the operation panel 4 of the second embodiment are different from the control configuration of the first embodiment shown in FIG.
A configuration in which 0 is added may be used. In this case, the ink supply amount is selected and set on the menu screen of the LCD display unit 49 of the operation panel 40, and the output signal from the ink supply amount adjustment key group 44 is transmitted and input to the control device 30C. Only at this time, the control device 30C may preferentially control the pump motor 10 based on an output signal from now on in the same manner as described above, and the control operation of the control device 30 may be temporarily stopped.

As an example of the overall configuration in this case, the ink supply amount adjustment key group 44 and the ink supply amount adjustment key group 4
4 to supply ink to the ink pool 27 in accordance with the output signal from
A control device 30C different from the control device 30 for controlling the pump motor 10 so as to change the supplied ink supply amount.
The control device 30C includes an ink supply amount adjustment key group 4
Only when an output signal from the control unit 30 is received, the pump motor 10 is controlled so as to change the ink supply amount in preference to the control operation of the pump motor 10 by the control device 30 (see claim 12). .

The printing method and the printing apparatus according to the present invention
As in the above-described embodiment, the operation is not limited to the printing method or the printing apparatus of the type in which the ink is supplied to the printing drum 21 by the operation of the pump motor 10 as the pump driving means for driving the ink pump 6. -2922
As shown in FIG. 2 and the like in JP-A-43, rotation transmission means using a plurality of gears for converting and transmitting a rotational driving force of a printing drum to a driving force for driving an ink pump as a pump driving means. Also, the present invention can be applied to a printing method and a printing apparatus of a type having an electromagnetic clutch that drives on / off the transmission of the rotational driving force to the ink pump. in this case,
The on / off timing of the electromagnetic clutch and the on / off timing of the pump motor 10 (or the ink pump 6) in the first embodiment, the first and second modifications, and the second embodiment have an equal relationship.

The printing method and the printing apparatus according to the present invention
In addition to the printing method and the heat-sensitive stencil printing apparatus of the embodiment described above, printing is performed only on one type of printing paper, such as a paper size A4 size, instead of the printing drum detachably mounted on the apparatus main body. The present invention is also applicable to a so-called A4-size special-purpose machine having a printing drum which is manufactured for the purpose and is fixed to the apparatus main body.

Further, the printing method and the printing apparatus according to the present invention are not limited to the above-described printing method and the thermosensitive stencil printing apparatus of the embodiment, but may be, for example, a printing drum as disclosed in JP-A-7-17013. The present invention is also applicable to a printing method or a printing apparatus having a configuration in which ink is supplied from outside of the printer, that is, a configuration in which ink is supplied to a plate-making master on a printing drum to form a print image on printing paper.

That is, according to the printing method of the present invention, when the absence of ink is detected by the ink presence / absence detecting means for detecting the presence / absence of ink to be supplied to the printing drum, the ink is supplied to the printing drum. The present invention can be applied to all printing methods for supplying ink to a printing drum by operating a pump driving unit for driving an ink pump (refer to a known part of claim 1). In addition, the printing apparatus according to claims 6 to 9 and 12 of the present invention comprises an ink presence / absence detecting means for detecting presence / absence of ink to be supplied to the printing drum, an ink pump for supplying ink to the printing drum, and an ink presence / absence detecting means The present invention can be applied to all printing apparatuses provided with a pump driving means for driving an ink pump to supply ink to the printing drum when the absence of ink is detected (see the known part of claim 6).

The printing method according to a fifth aspect of the present invention is a printing method for supplying ink to a printing drum by operating a pump driving means for driving an ink pump to supply ink to the printing drum. Section 5). The printing apparatus according to the tenth and eleventh aspects of the present invention is a printing apparatus including an ink pump that supplies ink to a printing drum, and a pump driving unit that drives the ink pump to supply ink to the printing drum. (See the known part of claim 10).

As described above, the present invention has been described with respect to the specific embodiments and the examples included therein. However, the configuration of the present invention is not limited to the above-described ones, It is obvious to those skilled in the art that various embodiments and examples may be configured in combination or alone, and various embodiments and examples may be configured according to the necessity, purpose, application, and the like within the scope of the present invention. .

[0095]

As described above, according to the present invention,
A new printing method and printing apparatus can be provided by solving the problems of the conventional printing method and printing apparatus as described above. The effects of each claim are as follows. According to the first aspect of the present invention, the pump driving means is provided when the ink pump is supplying ink to the printing drum by the operation of the pump driving means, and when the presence of ink is detected by the ink presence / absence detecting means. The amount of ink supplied to the printing drum after the presence of ink is detected by the ink detecting means is changed in accordance with the length of the operation time per unit time, thereby affecting the supply of ink to the printing drum. Regardless of the ink supply conditions, an appropriate amount of ink can always be supplied to the printing drum, so that a good print image density can always be obtained and energy saving can be achieved.

According to the second aspect of the present invention, when the ink pump is pumped by the operation of the pump driving means, the length of the entire driving time during the pumping is automatically changed. The effects of the invention described in Item 1 are exhibited.

According to the third aspect of the invention, when the ink pump is pumped by the operation of the pump driving means, the period between the pumping is automatically changed, so that the effect of the first aspect of the invention is exhibited.

According to the fourth aspect of the present invention, the operation speed of the pump driving means is automatically changed, so that the effects of the first aspect of the invention are exhibited.

According to the fifth aspect of the present invention, the ink supply amount is manually changed by the ink supply amount setting means for changing the ink supply amount to be supplied to the print drum, so that the ink supply to the print drum is performed. Irrespective of the ink supply conditions that affect the print quality, a desired amount of ink can be supplied to the print drum at the discretion of the user, so that a desired print image density can be obtained and energy can be saved.

According to the invention of claim 6, when the ink pump is supplying ink to the printing drum by the operation of the pump driving means, and when the presence of ink is detected by the ink presence / absence detection means, Control means for controlling the pump driving means so as to change the ink supply amount to be supplied to the printing drum after the output of the ink presence signal from the ink detecting means in accordance with the length of operation time per unit time of the pump driving means. Therefore, an appropriate amount of ink can always be supplied to the print drum regardless of the ink supply conditions that affect the supply of ink to the print drum, and a good print image density is always obtained. Also, energy saving can be achieved.

According to the seventh aspect of the invention, when the ink pump is pumped by the operation of the pump driving means, the control means automatically determines the length of the entire driving time while the ink pump is pumping. Since the pump driving means is controlled so as to change to the above, the effect of the invention described in claim 6 is achieved.

According to the eighth aspect of the present invention, when the ink pump is pumped by the operation of the pump driving means, the control means controls the pump driving means so as to automatically change the cycle between the pumping operations by the ink pump. Therefore, the effect of the invention described in claim 6 is exerted.

According to the ninth aspect of the present invention, the pump driving means is a pump driving motor having a variable rotation speed, and the control means controls the pump driving motor so as to automatically change the rotation speed of the pump driving motor. Claim 6
The effects of the described invention are exerted.

According to the tenth aspect of the present invention, the ink supply amount setting means for changing the ink supply amount to be supplied to the printing drum, and the ink supply amount according to the output signal from the ink supply amount setting means. Control means for controlling the pump drive means so as to change the amount of ink supplied to the print drum, regardless of ink supply conditions that affect the supply of ink to the print drum. And a desired print image density can be obtained, and energy saving can be achieved.

According to the eleventh aspect, since the ink supply amount setting means is provided on the operation panel, the operability of the ink supply amount setting means is improved.

According to the twelfth aspect of the present invention, the pump driving means is controlled so as to change the ink supply amount according to the output signal from the ink supply amount setting means. The other control unit has the pump driving unit to change the ink supply amount in preference to the control operation of the pump driving unit by the control unit only when receiving the output signal from the ink supply amount setting unit. Because of control, an appropriate amount of ink can always be supplied to the print drum regardless of the ink supply conditions that affect the supply of ink to the print drum, and a good print image density is always obtained. At the same time, energy can be saved, and a desired print image density can be obtained at any time by appropriate judgment of the user.

[Brief description of the drawings]

FIG. 1 is a cross-sectional front view of a main part of a thermosensitive stencil printing machine including a control configuration according to a first embodiment of the present invention.

FIG. 2 is a timing chart for explaining the first embodiment.

3A is a timing chart for explaining an example in which the operation time of the pump motor is increased in the first embodiment, and FIG. 3B is a timing chart for explaining an example in which the operation time of the pump motor is reduced in the first embodiment. .

FIG. 4 is a plan view of a main part of an operation panel according to a second embodiment.

FIG. 5 is a block diagram illustrating a control configuration according to a second embodiment.

FIG. 6 illustrates an LC of an operation panel according to a modification of the second embodiment.
It is a top view which shows only D display part partially.

FIG. 7 is an overall configuration diagram of a thermosensitive stencil printing apparatus to which Embodiments 1 and 2 of the present invention are applied.

FIG. 8 is a timing chart for explaining an ink supply control method in a conventional printing method and printing apparatus.

[Explanation of symbols]

DESCRIPTION OF REFERENCE NUMERALS 1 Ink presence / absence detection sensor as ink presence / absence detection means 2 Ink detection needle constituting ink presence / absence detection means 3 Ink container 6 Ink pump 10 Pump motor as pump drive means 14 Pumping frequency sensor 21 Printing drum 29 Ink supply device 30, 30A , 30B, 30C Control device as control means 31 CPU 32 RAM 33 ROM 34 Timer 40 Operation panel 44 Ink supply amount adjustment key group as ink supply amount setting means tE Unit time tEC Operating time of pump motor per unit time

Claims (12)

[Claims] When the absence of ink is detected by ink presence / absence detection means for detecting the presence / absence of ink to be supplied to a printing drum, the operation of a pump driving means for driving an ink pump to supply ink to the printing drum is performed. A printing method for supplying ink to the printing drum, wherein the operation of the pump driving means causes the ink pump to supply ink to the printing drum, and the presence of ink is detected by the ink presence / absence detecting means. The ink supply amount to be supplied to the printing drum after the ink detection unit detects the presence of ink is changed according to the length of operation time per unit time of the pump driving unit when the pump driving unit is operated. And printing method. 2. The printing method according to claim 1, wherein, when the ink pump is pumped by the operation of the pump driving means, the total driving time during the pumping is automatically changed. A printing method characterized by causing a printing operation. 3. The printing method according to claim 1, wherein, when the ink pump is pumped by operating the pump driving means, a cycle between the pumping is automatically changed. 4. The printing method according to claim 1, wherein the operating speed of said pump driving means is automatically changed. 5. A printing method for supplying ink to said printing drum by operating a pump driving means for driving an ink pump to supply ink to the printing drum, wherein the amount of ink supplied to the printing drum is changed. Wherein said ink supply amount is manually changed by said ink supply amount setting means. 6. An ink presence / absence detecting means for detecting the presence / absence of ink to be supplied to the printing drum, an ink pump for supplying ink to the printing drum, and the printing when the absence of ink is detected by the ink presence / absence detecting means. A pump driving means for driving the ink pump to supply ink to the drum, wherein the operation of the pump driving means causes the ink pump to supply ink to the printing drum, When the presence or absence of ink is detected by the ink presence / absence detection means, the ink is supplied to the printing drum after the ink presence signal is output from the ink detection means in accordance with the length of operation time per unit time of the pump driving means. Control means for controlling the pump drive means so as to change the amount of ink supply to be performed. Characteristic printing device. 7. The printing apparatus according to claim 6, wherein when the ink pump is pumped by the operation of the pump driving means, the control means controls the entire driving while the ink pump performs the pumping. A printing apparatus wherein the pump driving means is controlled so as to automatically change the length of time. 8. The printing apparatus according to claim 6, wherein when the ink pump is pumped by the operation of the pump driving means, the control means automatically changes a cycle between the pumps by the ink pump. A printing apparatus for controlling the pump driving means as described above. 9. The printing apparatus according to claim 6, wherein said pump driving means is a pump driving motor having a variable rotation speed, and said control means is configured to drive said pump to change said rotation speed automatically. A printing device for controlling a motor. 10. A printing apparatus comprising: an ink pump for supplying ink to a printing drum; and pump driving means for driving the ink pump to supply ink to the printing drum. Ink supply amount setting means for changing the amount, and control means for controlling the pump driving means so as to change the ink supply amount according to an output signal from the ink supply amount setting means. A printing device characterized by the above-mentioned. 11. The printing apparatus according to claim 10, wherein said ink supply amount setting means is provided on an operation panel. 12. The printing apparatus according to claim 6, 7, 8 or 9, wherein the ink supply amount setting means for changing the ink supply amount, and an output signal from the ink supply amount setting means, Controlling the pump driving means so as to change the ink supply amount, the control means being different from the control means, wherein the other control means receives an output signal from the ink supply amount setting means The printing apparatus according to claim 1, wherein the control unit controls the pump driving unit so as to change the ink supply amount in preference to the control operation of the pump driving unit by the control unit.