JPH02195B2 - - Google Patents

Description

Detailed Description of the Invention <Industrial Printing> The present invention relates to a printing device, and particularly to a printing device that can print on both the front and back sides of printing paper transferred from a paper feed section to a paper discharge section at one time. It is related to the device.

<Prior art> Examples of conventional printing devices of this type are those disclosed in Japanese Patent Application Laid-Open No. 58-20458 or Japanese Patent Application Laid-Open No. 56-58897.
The technique shown in the above publication is publicly known.

The former of the above-mentioned known techniques uses a single printing drum provided with printing type, and also uses a detection contact on the paper feed section side and a photoelectric converter whose optical path is blocked by the rotation of a shielding plate. This is a technology that prints in one color on one side of the printing paper that is transported.

Furthermore, in the latter of the above-mentioned known techniques, there are two
This is a technology that allows two-color (multi-color) printing to be performed in register and with high precision on one side of printing paper by arranging two printing drums in parallel and controlling them with one clutch mechanism.

<Problems to be Solved by the Invention> However, all of the above-mentioned known printing devices are technologies that perform highly accurate printing on only one side of printing paper, and in these technologies, it is difficult to print on one printing paper. There was a problem in that it was difficult to print on both the front and back sides of the printing paper due to transportation.

Furthermore, the former rotates a detection rotating shaft and a shielding plate attached to it when the printing paper being transferred comes into contact with the tentacle, and this shielding plate is detected by a photoelectric converter to control the rotation of the printing drum. The latter is a device that detects when the paper comes into contact with a contactor called a trip and the contactor blocks the phototube, and controls the rotation of the two printing drums with one clutch each. In both of these methods, errors are likely to occur because the feelers come into contact with the printing paper, and in particular, it is difficult to print with high precision at predetermined positions on both the front and back sides of the printing paper at the same time.

The printing device according to the present invention relates to a completely new technology developed in view of the above-mentioned problems.

<Means for Solving the Problems> The present invention provides an upper drum for printing on the front side of paper and a lower drum for printing on the back side of paper, each of which has an independent clutch between a paper feed section and a paper discharge section. A paper leading edge detection sensor is provided along the top and bottom of the transport line, and a paper leading edge detection sensor is provided between the paper feed section and the upper drum, and a cutout disk having a cutout at a predetermined position is attached to the drum shaft of the upper drum. At the same time, a notch detection sensor is arranged around the notch disk, and furthermore, the rotation of the upper drum and the lower drum can be controlled separately by detection signals from the paper leading edge detection sensor and the notch detection sensor. This is a double-sided printing device in a stamping machine characterized by being configured with a control section.

<Function> As described above, in the printing device according to the present invention,
Since an upper drum and a lower drum for printing are arranged along the upper and lower sides of the printing paper transport line, it is possible to print on both the front and back sides of the printing paper transported by these upper and lower drums at the same time. I can do it.

Further, in the printing apparatus of the present invention, the rotation of the printing paper or the upper drum is directly detected by the detection sensor without using a probe or the like, and the upper drum or the lower drum is rotated while being controlled by the control section. , can be accurately controlled, thereby preventing errors in printing register, etc.

In particular, in the present invention, a notch disc having a notch is attached to the drum shaft of the upper drum, and a notch detection sensor detects the state in which this notch rotates integrally with the upper drum, and this detection signal is detected. Since the rotation of the lower drum is controlled by the rotation of the lower drum, the rotation of the upper drum can be accurately transmitted to the rotation of the lower drum and the lower drum can be controlled. The timing of the rotation of the lower drum can be changed, thereby making it possible to print with extremely high precision on both the front and back sides of the printing paper.

Furthermore, in the printing apparatus of the present invention, independent clutches are provided for the upper drum and the lower drum, respectively.
Since these drums are individually controlled by the control section, the control is simple and accurate, and printing can be performed with high precision.

<Embodiment> An embodiment of the present invention will be described below based on the drawings. FIGS. 1 and 2 are a plan view and a side view of the main parts of a printing apparatus according to the present invention, including a paper feed section. 1
The printing paper 2 placed thereon is sent forward (to the right on the paper surface) by a paper feed roller 4 driven by a motor 3, and is ejected from a paper ejection section 5. In addition, paper 2 is provided in front of the paper feed section 1.
An upper drum 6 for printing the surface of the paper 2 is provided above the transport line of the paper 2, and as the upper drum 6 with a removable cassette printing plate 7 attached to a predetermined position is rotated, the lower part of the upper drum 6 is The paper 2 is passed between the press roller 8 and the paper 2 to print on the surface of the paper. Further, in front of the upper drum 6, a lower drum 9 for printing the back side of the paper is provided below the paper transport line, and a printing plate 10 is attached to the lower drum 9 at a predetermined position similarly to the upper drum 6. At the same time, a pressing roller 11 is provided on the upper part of the lower drum 9. Further, ink rollers 12, 12 are provided on the upper and lower drums 6, 9, respectively.

The power of the motor 3 is transmitted to the upper and lower drums 6 and 9 arranged as described above through a clutch 13 which is operated by a signal from a control section which will be described later. A fixing plate 1 having a recess 14 on the side surface as shown in FIG.
5 and a stop plate 18 having a convex part 16 that meshes with the recess 14 and a locking claw 17 around the periphery are attached to the drum shaft 20 with a spring 19 interposed therebetween so as to mesh with each other. A friction plate 21, a rotating gear 22, and a holding part 23 are attached to the outside. The fixed plate 15 is attached to the drum shaft 2
0 with screws or pins, and the stop plate 18 is configured to be able to slide slightly in the axial direction while maintaining the meshing state with the fixed plate 15, and the rotating gear 22 receives the driving force from the motor 3. However, it is rotatably attached to the drum shaft 20. Reference numeral 24 denotes a stop pawl that locks with the lock pawl 17 to stop the rotation of the drum, and is configured to move up and down by a connected magnet 25.

The other end of the drum shaft 20 is provided with a notched disk 27 having a notch 26 at a predetermined position as shown in FIG.
A notch detection sensor 28 is provided to detect when the notch 26 is fixed and rotated to a predetermined position. Furthermore, a leading edge detection sensor 29 is provided between the paper feed section 1 and the upper drum 6 to detect the leading edge of the printing paper 2 when it is fed. 30 receives the signals from the detection sensors 28, 29 and after a predetermined time, the upper and lower drums 6, 9
This is a control section that outputs a signal to operate the clutch 13 of. Note that 31 is an electromagnetic clutch provided to provide rotation to the paper feed roller 4.

To explain the operation of the stamping machine configured as above, the printing paper 2 stacked on the paper feed section 1 is fed forward one by one by the electromagnetic clutch 31 actuated by the start signal and the paper feed roller 4 rotated. The leading edge of the paper is detected by the leading edge detection sensor 29 at a predetermined position, and this detection signal is transmitted to the control section 30 . Upon receiving this signal, the control unit 30 sends a signal to release the clutch 13 of the upper drum 6 after the set time has elapsed, and this signal causes the magnet 25 to operate and the stop pawl 24 to move up and down.
3 is a locking pawl 17 and a stop pawl 24 as shown in FIG. 4a.
is engaged, the locking claw 17 locks the stopper plate 1
8 is prevented from rotating and stops, and the rotary gear 22 only idles. However, when the engagement is released, the spring 19 causes the stop plate 18 to rotate together with the friction plate 21, as shown in FIG. 4b. The rotation force of the rotating gear 22 is transmitted to the stop plate 18, the fixed plate 15, and thus the shaft 20 via the friction plate 21, so that the upper drum 6 rotates once. Printing is performed on the surface of paper 2. This upper drum 6
When the upper drum 6 rotates, the notched disk 27 attached to the other end of the upper drum shaft 20 also rotates, and the upper drum 6 rotates.
When the notch 26 is rotated by an angle θ°, the notch 26 is detected by the notch detection sensor 28, and this detection signal is transmitted to the control section 30. Upon receiving this signal, the control unit 30 operates the upper drum 6 by operating the magnet 25 of the clutch 13 that controls the rotation of the lower drum 9.
The lower drum 9 is rotated once by a clutch operation similar to the above, and a prescribed print is applied to a prescribed position on the back side of the paper 2. As a result, printing is applied to both the front and back sides of the printing paper 2, and the paper is discharged from the paper discharge section 5.

In the above process, the printing position on the front side of the paper 2 can be adjusted by adjusting the set time until the control unit 30 which receives the paper leading edge detection signal issues a clutch release signal for the upper drum 6, and also on the back side of the paper 2. The printing position can be determined by adjusting the relative position of the notch 26 of the notch disk 27 and the notch detection sensor 28 that detects the notch, so that the printing position can be determined by adjusting the position of the lower drum 9 relative to the upper drum 6.
The printing position can be adjusted by adjusting the rotation start timing. This detection signal simultaneously starts feeding the next sheet. Further, lateral adjustment can be easily performed by sliding the upper and lower drums 6, 9 left and right.

Furthermore, in the printing apparatus according to the present invention, it is of course possible to provide a paper thickness adjustment mechanism for operating the machine according to the thickness of the printing paper 2, and a mechanism for setting the number of printed sheets and a number of printed sheet counter mechanisms.

<Effects of the Invention> As described above, the printing apparatus according to the present invention includes an upper drum and a lower drum provided between the paper feed section and the paper discharge section, respectively.
Since these drums are configured to be rotated by signals from the control unit, it is possible to print on both the front and back sides of the printing paper during one process from paper feeding to paper ejection, and it is possible to print on both the front and back sides of the printing paper without touching it like in the past. Since the rotation of the printing paper or the upper drum is detected by two types of detection sensors and both the upper and lower drums are controlled separately without using a sensor, accurate control without errors is possible.
In particular, the rotation of the lower drum is controlled by detecting the notch in the disc attached to the drum shaft of the upper drum using a detection sensor, so the overall configuration is simple and allows the lower drum to be accurately synchronized with the upper drum. To be able to rotate, and to easily and accurately change the timing of rotation of the lower drum by shifting the position of the disk, thereby performing accurate printing on both the front and back sides of printing paper. Furthermore, since each of the upper and lower drums is equipped with a clutch and is individually controlled, each drum can be rotated independently and accurately, allowing highly accurate printing to be performed on both the front and back sides of the printing paper. In addition, the vertical printing position can be adjusted by adjusting the drum rotation start time on the control unit, and the horizontal printing position can be easily and freely adjusted by simply sliding the upper and lower drums left and right. It has the characteristics that it is possible to print date stamps, contents display, addressee signature stamps, etc. on the front and back sides of slips etc. very effectively in a short period of time.

[Brief explanation of drawings]

Fig. 1 is a plan view of the main parts of the stamping machine according to the present invention, Fig. 2 is a side view of the main parts, Fig. 3 is an explanatory perspective view of the clutch mechanism of the drum, and Fig. 4 is a partially cutaway cross-sectional view. FIG. 5 is an explanatory diagram of the operation of the clutch, in which a shows the drum in a stopped state and b shows the drum in a rotating state. FIG. It is a perspective view showing a state in which the notch has been detected after rotation. 1 is the paper feed unit, 2 is the printing paper, 3 is the motor, 4
is a paper feed roller, 5 is a paper ejection section, 6 is an upper drum,
7 and 10 are printing plates, 8 is an upper drum pressing roller,
9 is a lower drum, 11 is a lower drum pressing roller, 1
2 and 12' are ink rollers, 13 is a clutch,
14 is a concave portion of the fixing plate, 15 is a fixing plate, 16 is a convex portion of a stop plate, 17 and 24 are locking claws, 18 is a stop plate,
19 is a spring, 20 is a drum shaft, 21 is a friction plate, 22 is a rotating gear, 23 is a holding part, 25 is a magnet, 26 is a notch, 27 is a notched disk,
28 is a notch detection sensor, 29 is a paper leading edge detection sensor, 30 is a control section, and 31 is an electromagnetic magnet.

Claims (1)

[Claims] 1. An upper drum for printing on the front side of paper and a lower drum for printing on the back side of paper, each having an independent clutch between a paper feed section and a paper discharge section, are arranged along the top and bottom of a printing paper transport line, respectively. , and a paper leading edge detection sensor is provided between the paper feed section and the upper drum, a notch disk having a notch at a predetermined position is attached to the drum shaft of the upper drum, and a notch is provided around the notch disk. A detection sensor is provided, and a control section is further provided that can separately control the rotation of the upper drum and the lower drum based on detection signals from the paper leading edge detection sensor and the notch detection sensor. Double-sided printing device in a stamping machine.