JP2000136046A - Printer and print system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize printer and print system in which disturbance is not generated in paper feeding at a rear end part or a tip part of print paper, thereby prevents the lowering of image quality. SOLUTION: In the paper feeding upstream direction of a carriage 5, a feed roller 2a and pinch rollers 3a to 3c are arranged. In the downstream direction, a feed roller 2b and pinch rollers 3d to 3f are arranged. The upstream pinch rollers 3a to 3c are selected so as to be smaller than other rollers in rubber hardness. The center pinch roller 3b is provided so as to be offset in the downstream direction of the other pinch rollers 3a, 3c. Further, a downstream feed roller 2b is provided with a plate spring 40 for brake by contacting them each other. When a rear end of print paper P is away from the feed roller 2a, the rear end is gradually apart by the offset pinch rollers 3a to 3c and the print paper P is not sprung because rubber hardness is set to be smaller. Also when the print paper P is sprung, the downstream feed roller 2b is not easily rotated by the plate spring 40. Therefore, paper feeding pitch is not disturbed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer for feeding print paper in a paper feed direction and printing on the print paper by a printing means, and a print system using the printer.

[0002]

2. Description of the Related Art As an example of a conventional printer, a printer using printing paper coated with photosensitive microcapsules will be described. A printer using print paper coated with photosensitive microcapsules scans the print paper with a printer head having three types of light-emitting elements of red, green, and blue to form a latent image, and the latent image is formed. Further, the printing paper is developed by applying a mechanical pressure by a print roller. The printing paper is obtained by uniformly coating a photosensitive microcapsule having a diameter of about 4 microns on a base paper, coating an image receiving layer containing a color developing agent thereon, and further laminating a polyester film thereon. The microcapsules themselves are merely transparent gelatin microvessels that are light-transmissive and strong enough to be broken by the mechanical pressure of the print roller.

When one type of light among R, G, and B, that is, monochromatic light is selected and irradiated on a full-color printing paper coated with three types of photosensitive microcapsules, M, Y, C
Of the three types of photosensitive microcapsules, only the photosensitive microcapsules enclosing a photocurable substance having a complementary color relationship with the selected monochromatic light are cured in response to light, and the other two types are not cured. That is, when the light of R is irradiated, the photosensitive microcapsule of C hardens in response to the red light of the photocurable substance, and the other two types, that is, the photosensitive microcapsules of M and Y do not harden. When the pressure of the print roller is applied to the print paper in this state, the photosensitive microcapsules of M and Y are completely destroyed, but the photosensitive microcapsules of C are not destroyed or are incomplete depending on the degree of curing. Destroyed. For this reason, the M and Y coloring substances come into contact with the image receiving layer of the printing paper, and the area develops red mixed with M and Y. The color of the red color obtained by mixing M and Y changes depending on the degree of curing of the photosensitive microcapsule C. This is because, although incomplete, the photosensitive microcapsules of C are destroyed, and the color-forming substance for C comes into contact with the image receiving layer. Similarly, when the light of G is irradiated, a green color is obtained by mixing Y and C, and when the light of B is further irradiated, M and C are emitted.
And blue.

[0004] In short, when three types of light having different wavelengths, that is, one type of light of R, G, and B are selected and irradiated on a full-color printing paper coated with three types of photosensitive microcapsules, The region irradiated with the selected light emits a color of M and Y, Y and C, or a mixture of C and M. In addition, R, G, B
When two types of light are selected and irradiated, the region irradiated with the selected two types of light emits a color corresponding to one of M, Y, or C. The region not irradiated with any type of light exhibits black color because colors corresponding to all of M, Y, and C are performed. The color tone, saturation, and brightness of the print are adjusted by adjusting the intensity of irradiation light and the irradiation time.

A printer A 'for performing printing on a full-color print sheet coated with photosensitive microcapsules in accordance with the above-described process, for example, as shown in FIG. A carriage 105 having a printer head for forming a latent image and a print roller for applying pressure to and developing the printing paper P on which the latent image is formed; a carriage guide 104 for guiding the carriage in the scanning direction; And a part of a mechanism for feeding the printing paper P in one direction at a predetermined speed, provided on the upstream side of the carriage. Upstream feed roller 102
a, and the feed roller 1
02a, and an upstream pinch roller 103a for sandwiching the print paper P in cooperation with the feed roller 102b, and a downstream feed roller 102b provided on the downstream side of the carriage, and a print paper provided in opposition to the feed roller 102b in cooperation with the feed roller 102b. And a downstream pinch roller 103b sandwiching P.

As described above, in the configuration in which two feed rollers as a paper feed mechanism are provided upstream and downstream in the direction in which the print paper P is fed with the carriage 105 interposed therebetween, as shown in FIG. Even when the print paper P is disengaged from the upstream feed roller 102a, the print paper P can be fed because the downstream feed roller 102b and the pinch roller 103b still sandwich the print paper P. There is an advantage that printing can be performed up to the end of the image.

However, there is a problem that the feed paper P is momentarily disturbed at the moment when the print paper P comes off the upstream feed roller 102a and the pinch roller 103a. When the print paper P is relatively thick, especially the print paper coated with the photosensitive microcapsules has a thickness of 0.175 mm.
The moment it deviates from a, it is repelled in the feed direction, and the feed pitch is disturbed. This disturbance of the feed naturally appears as a decrease in image quality. There has been a demand for a print paper feeding mechanism that does not cause image deterioration while taking advantage of the fact that printing can be performed up to the edge of the print paper.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the conventional printer, and its main purpose is to print on a paper feed mechanism disposed before and after a printing unit. It is an object of the present invention to provide a printer and a printing system that do not disturb the paper feed when the end of the paper comes in contact with or separates from the paper, so that the image quality does not deteriorate.

[0009]

According to a first aspect of the present invention, there is provided a printing means for printing on print paper, and a printing means provided upstream of the printing means in a paper feeding direction. An upstream feed roller for moving the print paper in the paper feed direction, an upstream pinch roller facing the upstream feed roller and cooperating with the print paper, and a downstream of the printing means in the paper feed direction. A downstream feed roller that is provided on the side and moves the print paper in the paper feed direction, and a downstream pinch roller that opposes the downstream feed roller and cooperates to pinch the print paper. Measures for paper feed disturbance at the rear end of print paper among the upstream feed roller, upstream pinch roller, downstream feed roller, and downstream pinch roller Therefore, the hardness of the upstream pinch roller is smaller than that of the other rollers, or the hardness of the downstream pinch roller is set to be smaller than that of the other rollers in order to prevent paper feed disturbance at the leading edge of the print paper. I made the printer smaller. When measures are taken at both the front end portion and the rear end portion, the hardness of both the upstream pinch roller and the downstream pinch roller is made smaller than that of the other rollers.

According to a second aspect of the present invention, there is provided a printing means for printing on print paper, and an upstream means provided upstream of the printing means in the paper feed direction for moving the print paper in the paper feed direction. A feed roller, an upstream pinch roller that faces the upstream feed roller and cooperates to pinch the print paper, and is provided downstream of the printing unit in the paper feed direction, and moves the print paper in the paper feed direction. In a printer having a downstream feed roller to be moved, and a downstream pinch roller facing the downstream feed roller and cooperating to pinch the printing paper, the downstream feed roller is subjected to an external force received by the downstream feed roller. The printer was provided with a brake mechanism for preventing the rotation of the printer.

According to a third aspect of the present invention, there is provided a printing means for printing on print paper, and an upstream means provided upstream of the print means in the paper feed direction for moving the print paper in the paper feed direction. A feed roller, an upstream pinch roller that faces the upstream feed roller and cooperates to pinch the print paper, and is provided downstream of the printing unit in the paper feed direction, and moves the print paper in the paper feed direction. In a printer having a downstream feed roller to be moved and a downstream pinch roller opposed to the downstream feed roller and cooperating to pinch the print paper, measures are taken to prevent paper feed disturbance at the rear end of the print paper. In order to achieve this, the upstream pinch roller is constituted by a plurality of rollers, and among the plurality of rollers, the rotation axes of some of the rollers are different from the rotation axes of the other rollers. Also, in order to offset the paper feed direction downstream, or to prevent the paper feed disorder at the leading end of the print paper, the downstream pinch roller is constituted by a plurality of rollers, and a part of the plurality of rollers is used. The printer was constructed in such a manner that the rotation axis of one roller was offset upstream of the rotation axis of the other roller in the paper feed direction. Also, the tip,
When taking measures against both the rear end, use an upstream pinch roller,
The above measures are taken for the downstream pinch rollers.

In the third configuration, it is preferable that when the pitch at which the printer paper is fed is p, the offset amount d is approximately p <d <3p. The first to third configurations may be combined as appropriate to form a printer. The present invention is particularly suitable for a printer using print paper coated with photosensitive microcapsules because the print paper is thick, but can also be applied to printers based on other printing principles. As a printing means, any of a serial printer that prints by scanning a head and a line printer that prints in a line can be applied.

Still further, according to the present invention, there is provided a printer having the above-described configuration and an external device connected to the printer, transmitting and receiving signals between the printer and the external device, and printing by the printer. Configured.

[0014]

FIG. 1 is an enlarged sectional view of a printer according to a first embodiment of the present invention as viewed from the side. FIG.
Shows a plan view of the printer and print system. FIG.
2 shows a cross-sectional view of the printer as seen from the side where printer paper is discharged. In FIG. 2, A indicates a printer, and B indicates a digital camera. The printer A stores a plurality of print papers each coated with a photosensitive microcapsule in a cassette C, and has a function of feeding out the print papers one by one from the cassette C for printing. The digital camera B has a function of inputting an image and outputting the image to an external device through a video output terminal (or a digital output terminal). Printer A and digital camera B are connected by an interface cable. The form in which the printer A and the digital camera B are connected is referred to herein as a print system. In this print system, image data stored in the memory of the digital camera B is transmitted to a printer through an interface cable, and the image data is printed by a printer A on print paper P stored in a cassette C.

The printer A includes the following components. (A) Pickup roller 1 for feeding print paper P from cassette C (b) Upstream feed roller 2 for intermittently feeding print paper P fed by pickup roller 1
a and pinch rollers 3a, 3b, 3c (c) Downstream feed roller 2b, and pinch rollers 3d, 3e, 3f (d) Carriage guide 4 (e) provided in a beam shape between feed rollers 2a, 2b (F) A carriage 5 guided and slid by the carriage guide 4 (f) A belt wrapping mechanism 6 provided on the upper surface of the carriage guide 4 to reciprocate the carriage 5 (g) The pinch rollers 3a, 3b, 3c on the upstream side On the downstream side, a placing table 7 that horizontally supports the printing paper P (h) is attached to the carriage 5 and selectively irradiates light of a specific wavelength to the printing paper P guided on the loading table 7. Light emitting diode 8 for forming a latent image
a, 8b, 8c (i) The mounting table 7 and the pinch roller 3d on the downstream side
A platen 9 which comes in line contact with the print paper P between 3e and 3f and receives it from below (j) is mounted on the carriage 5 and rolls on the platen 9 by scanning movement of the carriage 5 to print. The two rolling rollers 12a, 1a, which press the paper P and crush microcapsules which have not been hardened due to the specific light
2b (k) A heater 14 provided on the downstream side of the downstream feed roller 2b, which is pressed by a leaf spring and heats the upper surface of the printing paper P to accelerate the color forming reaction of the color forming material in contact with the image receiving layer. (L) Linear sensor 21 and bar code sensor 22 provided on bracket of carriage 5 (m) Scale 23 provided corresponding to linear sensor 21 (n) Motor 15 for driving each movable component (o) 20 A gear train 16 composed of a single gear and a one-way clutch 16 (p) A controller 17 that controls each unit (q) A battery 18 that supplies power to each unit (Description of Configuration of Each Unit) Next, details of each unit will be described.

The gear train 16 transmits the forward rotation and the reverse rotation of the motor 15 to the movable parts. In particular, by the combination of the gear train 16 and the belt winding mechanism 6, the carriage 5 can be reciprocated only by continuously rotating the motor 15. At the same time, when the carriage 5 reciprocates near both ends, the feed rollers 2a and 2b can give a minute feed to the print paper P. By adopting this configuration, the operation control of the motor 15 is facilitated, and it is possible to realize an ultra-small size that can be placed on the palm.

When an ON signal of a print switch of the printer is input, the controller 17 controls each unit so as to perform an operation for preparing for printing. First, the controller 17 inputs image data from the digital camera B, and calculates this as an electric signal for causing the light emitting diodes 8a, 8b, 8c to emit light. Next, a motor drive signal for rotating the motor 15 clockwise is output. As a result, the pickup roller 1 and the feed rollers 2a and 2b rotate, and first, the pickup roller 1 feeds out the print paper P from the cassette C, and then the feed roller 2a and the pinch rollers 3a, 3b and 3c sandwich the print paper P. I will pay out. When a paper sensor (not shown) detects the leading edge of the print paper P, the controller 17 inputs this detection signal and stops outputting the motor drive signal.

Next, the controller 17 controls each unit so as to perform an operation for printing. As described above,
Pickup roller 1 moves print paper P from cassette C
Immediately after feeding out, the controller 17
And outputs an electric signal corresponding to the image data to the light emitting diodes 8a, 8b and 8c at the same time. An electric signal for causing the light emitting diodes 8a, 8b, 8c to emit light is configured to be output in synchronization with a signal from which the linear sensor 21 reads the scale of the scale 23.

The print paper P used in the printer according to the present invention is called a photosensitive microcapsule type printer paper. This printer paper is obtained by uniformly coating a photosensitive microcapsule having a diameter of about 4 microns on a base paper, coating an image receiving layer containing a color developing agent thereon, and further laminating a polyester film thereon.
The microcapsules themselves are merely transparent gelatin microvessels that are light-transmissive and strong enough to be broken by the mechanical pressure of the print roller.

The color-forming substance encapsulated in the microcapsules is a transparent leuco dye, which is a substance that forms color when it comes into contact with an image receiving layer containing a color developer. The color-forming substances correspond to the three primary colors of light, that is, red (R), green (G), and blue (B).
That is, three types of magenta (M), yellow (Y), and cyan (C) are prepared. The photo-curing material that is encapsulated in the microcapsule in combination with the color-forming substance is a light of a color that is complementary to the color presented by the color-forming substance coming into contact with the image receiving layer,
That is, a substance that is cured by light having a specific wavelength is selected. That is, a photo-curable substance that cures when irradiated with green light (G) is selected as the magenta (M) color-forming substance that absorbs green and exhibits reddish purple. Similarly, a color-forming substance for yellow (Y) that absorbs blue-violet is a photo-curing substance that cures when irradiated with blue light (B), and a cyan (C) that absorbs red and exhibits blue-violet. As the color-forming substance, a photo-curable substance that cures when irradiated with red light (R) is selected.
Accordingly, there are three types of photosensitive microcapsules, M, Y, and C. Therefore, there are two types of special printing paper: mono-color for only one type of photosensitive microcapsule and 256-color full-color for three types of photosensitive microcapsules. There is for sensitivity. The principle of coloring of such special print paper is as follows.

For example, when one type of light of R, G, and B, that is, monochromatic light is selected and irradiated on a special printing paper for full color coated with three types of photosensitive microcapsules,
Of the three types of photosensitive microcapsules of M, Y, and C, only the photosensitive microcapsules enclosing a photocurable substance having a complementary color relationship with the selected monochromatic light are cured in response to light, and the other two are cured. The type does not cure. That is, when the light of R is irradiated, the photosensitive microcapsule of C hardens in response to the red light of the photocurable substance, and the other two types, that is, the photosensitive microcapsules of M and Y do not harden. When the pressure of the roller is applied to the special printing paper in this state, the photosensitive microcapsules of M and Y are completely destroyed, but the photosensitive microcapsules of C are not destroyed or incompletely depending on the degree of curing. Destroyed. For this reason, the M and Y coloring substances come into contact with the image receiving layer of the special printing paper, and the area develops red mixed with M and Y. The red color that mixes M and Y is
The color tone changes depending on the degree of curing of the photosensitive microcapsule C. This is because, although incomplete, the photosensitive microcapsules of C are destroyed, and the color-forming substance for C comes into contact with the image receiving layer. Similarly, when G light is irradiated, Y and C
And green when mixed, and when irradiated with B light, M
And C are mixed to give a blue color.

In short, a special printing paper for full color coated with three types of photosensitive microcapsules, R, G,
When one type of light in B is selected and irradiated, the region irradiated with the selected light is M and Y, Y and C or C and M
Is developed into a mixed color. Further, when two types of light of R, G, and B are selected and irradiated on the full-color special print paper, an area irradiated with the selected two types of light is one of M, Y, or C. It develops into a color corresponding to one. Areas that were not irradiated with any type of light were M,
Since color development corresponding to all of Y and C is performed, black is exhibited. The color tone, saturation, and brightness of the print are adjusted by adjusting the intensity of irradiation light and the irradiation time.

The cassette C stores, for example, about ten sheets of the printing paper P in a stacked manner, and is provided detachably from the printer A. This cassette C
Is used by being inserted from a cassette insertion opening opened in the case of the printer A. When the cassette C is inserted into the cassette insertion slot, the printing paper P is configured to come into close contact with the pickup roller 1.

The pickup roller 1 is a rubber roller and is mounted on a support shaft so as to freely rotate. When the motor 15 rotates clockwise, the rotation of the support shaft is transmitted to the pickup roller 1, so that the pickup roller 1 rotates in a direction in which the print paper P is fed out. Feed rollers 2a, 2b and pinch roller 3a
Nos. 3f are fixed by attaching a rubber cylinder to a steel shaft. Each of the upstream pinch rollers 3a, 3b, and 3c includes three independent rollers, and is arranged below the upstream feed roller 2a so as to freely rotate.
Further, the feed roller 2a is supported by a spring so as to press the feed roller 2a. As shown in FIG. 4, the center pinch roller 3b is provided with its center offset from the other two pinch rollers 3a, 3b by d in the print paper feed direction. It is desirable that the offset amount d be substantially p <d <3p, where p is the pitch at which the print paper P is fed. In this embodiment, p = 0.17 mm and d = 0.35 mm. Downstream pinch roller 3
d, 3e, 3f are arranged below the downstream feed roller 2b, and are supported by a spring so as to press the feed roller 2b. These pinch rollers are all arranged coaxially.

Of these feed rollers and pinch rollers, the rubber hardness of the upstream and downstream feed rollers 2a and 2b was 90 degrees, and the rubber hardness of the downstream pinch rollers 3d, 3e and 3f was 70 degrees. Upstream pinch rollers 3a, 3
The rubber hardness of b and 3c was 25 degrees, which was softer than the hardness of the other rollers. The downstream feed roller 2b is
As will be described later, the drive side is connected to the drive side by a one-way clutch, so that the drive side can freely rotate with respect to a force that attempts to move the lower surface of the roller in the sheet feeding direction. In order to prevent this movement, as shown in FIG. 7, a leaf spring 40 for braking is provided on the feed roller 2b so as to come into contact therewith. The feed roller 2b is configured such that its rotation is hindered by friction with the brake leaf spring 40. The frictional force is generated when the rear end of the print paper reaches the upstream feed roller 2a and the pinch rollers 2a, 2b,
It is necessary to keep the downstream feed roller 2b to such an extent that the downstream feed roller 2b does not easily rotate depending on the force generated when the print paper deviates from 2c in the paper feed direction.

The belt wrapping mechanism 6 includes a driving timing pulley 6a and a driven timing pulley 6b mounted on a vertical shaft provided on the carriage guide 4, and a timing belt 6c wrapped around both pulleys 6a, 6b.
Consists of A circulation pin 25 is provided on the timing belt 6c. The carriage 5 is guided by the beam-shaped carriage guide 4 and is provided so as to reciprocate in the scanning direction. Circulation pin 2 provided on timing belt 6c
Reference numeral 5 is inserted into a long hole 5 a provided in the carriage 5. When the motor 15 rotates counterclockwise, the motor 1
The rotation of 5 is transmitted to the driving-side timing pulley 6a via the gear train 16, and the timing belt 6c runs counterclockwise when viewed in a plane direction. The carriage 5 includes the circulation pin 2
The engagement with the print belt 5 follows the travel of the timing belt 6c and performs reciprocal scanning in a direction orthogonal to the feed direction of the print paper P.

The carriage 5 is provided with an LED mounting plate at the lower portion thereof, and the light emitting diodes 8a, 8b, 8c are mounted on the LED mounting plate. These light emitting diodes are all high-brightness light emitting diodes. Three light emitting diodes 8a are provided and emit light of a red wavelength. As described above, the red light emitted by the light emitting diode 8a cures the photo-curing material enclosed together with the cyan-coloring material of the microcapsules applied to the printing paper P. Also, three light emitting diodes 8b are provided, and emit light of a green wavelength. The green light emitted by the light-emitting diode 8b cures the photo-curable substance enclosed together with the color-forming substance that develops magenta. Further, the light emitting diode 8c
Are also provided, and emit light of a blue wavelength. The blue light emitted by the light-emitting diode 8c cures the photo-curing material enclosed together with the coloring material that develops yellow. Light emitted from these light emitting diodes 8a, 8b, 8c is applied to the print paper P through pinholes formed in the carriage 5. Note that the number of light emitting diodes may be changed according to the required light intensity.

The controller 17 receives image data from the digital camera B and calculates the amount of light emitted from the light emitting diodes 8a, 8b and 8c based on the image data. When the carriage 5 moves in the scanning direction, the controller 17 causes the light emitting diodes 8a, 8b, 8c to emit light in accordance with the image data. At this time, control is performed so that the linear sensor 21 emits light in synchronization with a signal obtained by reading the scale of the scale 23.

Platen 9 and rolling rollers 12a, 12b
Constitutes a pressurizing unit that presses one point of the print paper P with a high pressure to crush the microcapsules applied to the print paper P. Platen 9
Are arranged in a direction orthogonal to the feed direction of the print paper P, and a portion of the portion that comes into contact with the rolling roller 12a has a cross-sectional shape along the feed direction of the print paper P that is upwardly convex. . Also, with the spring fixed to the chassis,
It is lifted in the direction of the rolling roller 12a. The contact between the platen 9 and the rolling roller 12a is a point contact, and the spring pressure of the spring is adjusted so that the contact pressure becomes about 800 g. When the carriage 5 is located at both ends, the platen 9 is moved downward by the cam mechanism so that the rolling roller 12a is separated from the printing paper P.

The gear train 16 includes a Geneva gear 16r described later.
As described above, while the rolling roller 12a is separated from the print paper P, one tooth of the Geneva gear 16r is engaged with the gear 16s. Thus,
When the print paper P is not sandwiched between the platen 9 and the rolling roller 12a, the rotation of the motor 15 is transmitted to the pickup roller 1 and the feed rollers 2a and 2b, and the feed rollers 2a and 2b feed the print paper P by a small size. Is to give.

The heater 14 includes feed rollers 2a, 2b
The printing paper P sent by the above is passed between a leaf spring and the printing paper P and heated. The coloring material of the crushed microcapsules of the printing paper P comes into contact with the image receiving layer, and is further heated by the heater 14 to accelerate the coloring. In this embodiment, the heater 14 is provided on the downstream side of the downstream feed roller 2b. However, if the print paper P is still sandwiched between the heater 14 and the leaf spring, the heater 14 is overheated. 14 is preferably provided on the upstream side of the downstream feed roller 2b. (Description of Configuration and Operation of Gear Train) Next, the gear train 1
6 will be described in detail with reference to FIG. 5 and FIG.

As shown in FIG. 5, first, the rotation of the motor 15 is controlled by the gear 16a (number of teeth: 12) and the gear 16b (number of teeth: 84).
Is transmitted to the shaft 31 by meshing with the shaft. Next, the rotation of the shaft 31 is transmitted to the gear 16c via the one-way clutch 32a.
(30 teeth). Further, the rotation of the gear 16c is performed by the gear 16d (the number of teeth 20) and the gear 16e (the number of teeth 30).
Is transmitted to the bevel gear 16f (30 teeth) fixed coaxially to the gear 16e. Furthermore, bevel gear 1
The rotation of the gear 6f is performed by meshing with the bevel gear 16g (the number of teeth: 15), and the gear 16h fixed to the bevel gear 16g.
(15 teeth). Further, the rotation of the gear 16h is transmitted to the gear 16i (the number of teeth 15). Gear 16i
Is a driving timing pulley 6a of the belt winding mechanism 6.
The carriage 5 reciprocates as the belt wrapping mechanism 6 travels.

Next, each time the carriage 5 is positioned at the end and makes a U-turn, the rotation of the motor 15 is controlled by the pickup roller 1.
And a power transmission path for transmitting the power to the feed rollers 2a and 2b. As shown in FIG. 6, the rotation of the motor 15 is controlled by the engagement of the gears 16a and 16b.
1 is transmitted. Next, the rotation of the shaft 31 is transmitted to the gear 16p (the number of teeth is 12) via the one-way clutch 32a. Further, the rotation of the gear 16p is transmitted to the Geneva gear 16r (1 tooth) fixed coaxially with the gear 16q by meshing with the gear 16q (30 teeth). further,
The rotation of the Geneva gear 16r is transmitted to the gear 16s (the number of teeth is 18). However, since the Geneva gear 16r has one tooth, every time the Geneva gear 16r makes one rotation, the gear 16s rotates by one tooth. Will only rotate. Thus, the continuous rotation of the Geneva gear 16r is converted into intermittent rotation of the gear 16s. The intermittent rotation of the gear 16s is transmitted to a gear 16t (12 teeth) fixed coaxially with the gear 16s. Further, the intermittent rotation of the gear 16t is the gear 1
By meshing with the gear 6u (the number of teeth 38), it is transmitted to the gear 16n via a one-way clutch 32d provided between the shaft of the gear 16u and the shaft hole of the gear 16n. Further, the intermittent rotation of the gear 16n is transmitted to the feed roller 2a coaxially fixed to the gear 16m and the feed roller 2b coaxially fixed to the gear 16o by the engagement of the gear 16m and the gear 16o. Thus, each time the carriage 5 is positioned at the end and makes a U-turn, the feed rollers 2a, 2b
Is rotated by a minute angle to feed the print paper P by a minute size every time.

The one-way clutch 32d allows the downstream-side feed roller 2b to freely rotate with respect to a force that attempts to move the lower surface of the roller in the sheet feeding direction. However, as described above, the feed roller 2b is provided so as to be in contact with the brake leaf spring 40, so that when the rear end of the print paper comes off the upstream feed roller 2a and the pinch rollers 2a, 2b, 2c. Even if a force for pushing the print paper in the paper feed direction is generated, the print paper is not rotated.

Next, the operation of the printer according to the present invention will be described by organizing the contents already described. During printing, the motor 15 rotates counterclockwise. The rotation of the motor 15 is transmitted to the belt winding mechanism 6 via a power transmission path of the gear train 16. The carriage 5 starts reciprocating as the belt winding mechanism 6 travels. At the same time, the rotation of the motor 15 is transmitted to the pickup roller 1 and the feed rollers 2a and 2b via the power transmission path of the gear train 16.

While the carriage 5 is reciprocating, the light emitting diodes 8a, 8b, 8c irradiate the printing paper P with light corresponding to the image data to form a latent image on the printing paper. At the same time, the rolling roller 12a presses the print paper P linearly to crush the uncured microcapsules and perform development. On the other hand, the carriage 5
Are at both ends, the feed rollers 2a and 2b feed the print paper P by a very small size.

The heater 14 heats the print paper P. The color developing material of the crushed microcapsules of the print paper P comes into contact with the image receiving layer, and is further heated by the heater 14 to accelerate the color development. By repeating the above operation, printing is performed on the entire surface of the print paper P.
Next, the operation when the print sheet comes off the upstream feed roller 2a will be described with reference to FIG.

In FIG. 7, position a represents the position of the rear end of the print paper P at a certain point in time. In this state,
The rear end of the print paper P is nipped by the upstream feed roller 2a and the upstream pinch rollers 3a, 3b, 3c. Of course, the downstream feed roller 2b and the downstream pinch rollers 3d, 3e, 3f also hold the print paper P.

When the paper is fed in this state, in the next state, the trailing end of the printing paper P moves to the position b which has moved downstream from the position a by the paper feed pitch p = 0.17 mm. At the moment when the trailing edge of the print paper P is disengaged from the pinch rollers 3a and 3c during the movement, the conventional printer has a phenomenon that the printer paper P "flicks" in the paper feed direction. Since the rubber hardness of the roller was set as soft as 25 degrees, the repelling force could be considerably reduced. The center pinch roller 3b among the upstream pinch rollers has a d = 0.
Since it is offset by 35 mm, the print paper P
Is released from the pinch rollers 3a and 3c, but is still nipped by the pinch rollers 3b, and is not repelled. Furthermore, even if a repelling force is generated, the downstream side feed roller 2b
Is in contact with the leaf spring 40 for the brake,
Free rotation does not occur. For this reason, the print paper P is fed exactly by one pitch p, and the paper feed is not disturbed.

When the paper is further fed, the print paper P comes off the center pinch roller 3b, but the pinch roller 3b has a rubber hardness of 25 as described above, so that the repelling force is increased. Is small. Further, since the pinch roller 3b is only about 1/3 the width of the entire width, the repelling force is further reduced. The functions of the downstream feed roller 2b and the leaf spring for brake 40 are as follows.
As described above.

In this embodiment, p = 0.17 mm, d
= 0.35 mm, which is almost the same as d = 2p. In this state, the print paper gradually comes off the pinch roller by two consecutive paper feeds. However, depending on design conditions relating to other parameters, when the next feed is performed from the first position, the pinch roller may be disengaged from all pinch rollers. Therefore, it is necessary to adjust the offset amount d within a range of 3p or less.

As described above, in this embodiment, even if the rear end of the printing paper comes off the upstream feed roller, accurate paper feeding is performed and the pitch is not disturbed. Therefore, the printing quality does not deteriorate even at the rear end of the print paper. Note that, in the above embodiment, a part of the upstream pinch roller was provided with an offset, the rubber hardness of the upstream pinch roller was reduced, and a brake leaf spring was provided on the downstream feed roller. All measures were taken. However, depending on the conditions, it may be possible to obtain a sufficient effect with only some measures,
Not all need to be adopted at the same time. Either one may be selected and adopted. (Other Embodiments) According to the above-described embodiment, it is possible to prevent the paper feed from being disturbed at the rear end of the print paper. By changing the configuration as described below, it is possible to prevent the paper feed from being disturbed at the leading end of the print paper.

For example, the rubber hardness of the downstream pinch roller is set to 25 degrees in the same manner as in the above embodiment, and the center pinch roller 3e is moved in the paper feed upstream direction by an offset amount d having a relationship of substantially p <d <3p. Provided offset. With this configuration, the leading end of the print paper P is connected to the downstream feed roller 2 b and the downstream pinch roller 3.
Since d, 3e and 3f are eaten with a small force, they are not pushed back to the upstream side. Therefore, it is possible to prevent the paper feed from being disturbed at the leading end of the print paper, and the print quality is not degraded.

The above embodiment was carried out in a printer using print paper coated with photosensitive microcapsules. However, the present application has the same effect as long as the printer has a configuration in which two feed rollers are provided on the upstream side and the downstream side to feed the print sheet and a printing unit is provided between them. For example, a line printer in which printing means are arranged in a line may be used. The printing paper may use plain paper. For example, postcards or OHP
(Overhead projector) This is particularly effective for a printer using relatively thick print paper such as a sheet.

[0045]

As described above, in the printer according to the present invention, the printing means for printing on the printing paper and the printing means are provided upstream of the printing means in the paper feeding direction, and move the printing paper in the paper feeding direction. An upstream feed roller to be moved, an upstream pinch roller facing the upstream feed roller and cooperating to pinch the print paper, and a print paper provided downstream of the printing means in the paper feed direction for moving the print paper in the paper feed direction. A downstream feed roller, and a downstream pinch roller facing the downstream feed roller and cooperating with the downstream pinch roller, wherein the upstream feed roller, the upstream pinch roller, the downstream feed roller, Among the side pinch rollers, the hardness of the upstream pinch roller was set smaller than that of the other rollers. Alternatively, the hardness of the downstream pinch roller is set smaller than the other rollers.

Alternatively, the printer is provided with a brake mechanism for preventing the feed roller from rotating due to an external force applied to the downstream feed roller. Alternatively, in the printer, the upstream pinch roller is constituted by a plurality of rollers, and among the plurality of rollers, the rotation axes of some of the rollers are offset downstream of the rotation axes of the other rollers in the paper feeding direction. Alternatively, the downstream pinch roller is constituted by a plurality of rollers, and among the plurality of rollers, the rotation axes of some of the rollers are offset upstream of the rotation axes of the other rollers in the paper feeding direction.

Alternatively, a printer was constituted by appropriately combining these constitutions. According to the printer configured as described above, since the rubber hardness of the pinch roller is set to be soft, even when the print paper comes off the upstream pinch roller, for example, the print paper may be flipped in the downstream direction. Absent. Further, since a part of the upstream pinch roller is offset, the force with which the print paper is nipped gradually decreases with each paper feed, and the force for repelling the print paper in the downstream direction also decreases.
Further, since the downstream feed roller is provided with a leaf spring for a brake, even if a force for repelling the print sheet in the downstream direction is generated, the print sheet is not fed in the downstream direction more than the feed pitch. As described above, even at the rear end of the print paper, the print paper can be fed by exactly one pitch, and the paper feed is not disturbed. Therefore, the image quality does not deteriorate even at the rear end of the print paper. Further, since a part of the downstream pinch roller is offset, the leading end of the print sheet bites the roller with a small force, and is not pushed back to the upstream side. Therefore, it is possible to prevent the paper feed from being disturbed at the leading end of the print paper, and to realize a printer in which the image quality does not deteriorate.

Further, a printing system is constructed by connecting the printer having the above-described configuration and an external device to the printer. This printing system also has the same effect as the printer.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view of a printer according to a first embodiment of the present invention as viewed from a side.

FIG. 2 is a plan view showing a printer and a printing system according to the first embodiment of the present invention.

FIG. 3 is a cross-sectional view of the printer according to the first embodiment of the present invention as viewed from a side where printer paper is discharged.

FIG. 4 is an explanatory diagram showing an arrangement of an upstream pinch roller in the printer according to the first embodiment of the present invention.

FIG. 5 is a conceptual diagram illustrating a first power transmission path of a gear train employed in the printer according to the first embodiment of the present invention.

FIG. 6 is a conceptual diagram for explaining a second power transmission path of a gear train employed in the printer according to the first embodiment of the present invention.

FIG. 7 is an explanatory diagram for explaining an operation of the printer according to the first embodiment of the present invention in a state in which printer paper is disengaged from an upstream pinch roller.

FIG. 8 is an enlarged cross-sectional view of a conventional printer viewed from a side.

FIG. 9 is an enlarged cross-sectional view of a feed roller portion of a conventional printer as viewed from a side.

[Explanation of symbols]

Reference Signs List A Printer B Digital camera C Cassette P Print paper 1 Pickup roller 2a, 2b Feed roller 3a, 3b Pinch roller 4 Carriage guide 5 Carriage 5a Elongated hole 6 Belt winding mechanism 6a Driving side timing pulley 6b Driving side timing pulley 6c Timing belt 7 Mounting table 8a, 8b, 8c Light emitting diode 9 Platen 12a, 12b Rolling roller 14 Heater 15 Motor 16 Gear train 16a-16e, 16h-16q, 16s-16u
Gear 16r Geneva gear 16f-16g Bevel gear 17 Controller 18 Battery 21 Linear sensor 22 Barcode sensor 23 Scale 25 Circulation pin 32a, 32b, 32c, 32d One-way clutch

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] June 18, 1999 (1999.6.1
8)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

6. claims 1 and printer described in claim 5 is constituted by an external device connected to the printer, send and receive signals to and from the printer and an external device, said printer A printing system characterized in that the printing system is configured to perform printing. ────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] November 1, 1999 (1999.11.
1)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

Claims (7)

[Claims] A printing means for printing on print paper; an upstream feed roller provided upstream of the print means in a paper feed direction for moving the print paper in the paper feed direction; An upstream pinch roller facing the roller and cooperating to pinch the print paper; and a downstream feed roller provided downstream of the printing unit in the paper feed direction to move the print paper in the paper feed direction. A printer comprising: a downstream pinch roller facing the downstream feed roller and cooperating to pinch the print sheet; wherein the upstream feed roller, the upstream pinch roller, the downstream feed roller, and the downstream pinch roller A printer characterized in that the hardness of the upstream pinch roller is smaller than that of the other rollers. 2. A printing means for printing on print paper, an upstream feed roller provided upstream of the printing means in the paper feed direction, and for moving the print paper in the paper feed direction; An upstream pinch roller facing the roller and cooperating to pinch the print paper; and a downstream feed roller provided downstream of the printing unit in the paper feed direction to move the print paper in the paper feed direction. A printer comprising: a downstream pinch roller facing the downstream feed roller and cooperating to pinch the print sheet; wherein the upstream feed roller, the upstream pinch roller, the downstream feed roller, and the downstream pinch roller A printer wherein the hardness of the downstream pinch roller is smaller than that of the other rollers. 3. A printing means for printing on printing paper, an upstream feed roller provided upstream of the printing means in the paper feeding direction, and for moving the printing paper in the paper feeding direction; An upstream pinch roller facing the roller and cooperating to pinch the print paper; and a downstream feed roller provided downstream of the printing unit in the paper feed direction to move the print paper in the paper feed direction. A printer having a downstream pinch roller facing the downstream feed roller and cooperating with the downstream feed roller, the brake mechanism for preventing the downstream feed roller from rotating due to an external force received by the downstream feed roller. A printer comprising: 4. A printing means for printing on print paper, an upstream feed roller provided upstream of the printing means in the paper feed direction, and for moving the print paper in the paper feed direction; An upstream pinch roller facing the roller and cooperating to pinch the print paper; and a downstream feed roller provided downstream of the printing unit in the paper feed direction to move the print paper in the paper feed direction. A printer comprising: a downstream pinch roller facing the downstream feed roller and cooperating to pinch the print sheet; wherein the upstream pinch roller is constituted by a plurality of rollers, and a part of the plurality of rollers is provided. Wherein the rotation axis of one of the rollers is offset downstream of the rotation axis of the other roller in the paper feed direction. 5. A printing means for printing on print paper, an upstream feed roller provided upstream of the printing means in a paper feed direction, and for moving the print paper in the paper feed direction; An upstream pinch roller facing the roller and cooperating to pinch the print paper; and a downstream feed roller provided downstream of the printing unit in the paper feed direction to move the print paper in the paper feed direction. A printer comprising: a downstream pinch roller facing the downstream feed roller and cooperating to pinch the print sheet; wherein the downstream pinch roller is constituted by a plurality of rollers, and a part of the plurality of rollers is provided. Wherein the rotation axis of one of the rollers is offset upstream of the rotation axis of the other roller in the paper feed direction. 6. When the pitch at which the print paper is fed is p, the offset amount d is substantially p <d <3p.
The printer according to claim 4 or 5, wherein 7. The printer according to claim 1, further comprising: an external device connected to the printer, for transmitting and receiving signals between the printer and the external device. A printing system characterized in that the printing system is configured to perform printing.