JPH03142265A - Photographic printing apparatus - Google Patents

Abstract

PURPOSE:To prevent that a rear end of a recording paper is rolled up by the step difference and the shock is added to a printing means by letting a flexible guide member spread between an end part at the downstream side of a rotating direction of a guide member and the printing means, which communicates with an inner peripheral surface of the guide member and encircles a rotary roller. CONSTITUTION:A guide surface 23a is provided coaxially with a platen roller 21 having a recording paper 22 would around an outer peripheral surface thereof. The guide surface 23a has a larger diameter than the platen roller 21. The printing apparatus is constituted in the structure including a fixed guide 23 having a plurality of pressing rollers 24 to press the recording paper 22 against the platen roller 21 and, a thermal head 28 having an array of heat generating bodies 29 and supported to be in contact with or detached from the recording paper 22 on the platen roller 21 via an ink sheet 25. The fixed guide 23 is provided from a predetermined position downstream in the rotating direction of the thermal head 28 over to a position spaced upstream from the predetermined position. Accordingly, the printing state is kept uniform, with improving the printing quality so much.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a printing device that is suitably implemented in a thermal transfer printing device or the like that prints by pressing a thermal head against a recording paper on a platen roller via an ink sheet. Regarding.

BACKGROUND OF THE INVENTION FIG. 4 is a side view showing the i-precepts related to the thermal head 8 in a conventional thermal transfer printing device. A conventional thermal transfer printing device includes a platen roller 1 having a recording paper 2 wrapped around its outer circumferential surface and rotated in the direction of arrow R1 by a driving means (not shown), and a concentric guide surface having a diameter larger than that of the platen roller 1. 3a and a plurality of pressing rollers 4 for pressing the recording paper 2 toward the platen roller 1, and a heating element 9 arranged in a row to apply ink to the recording paper 2 on the platen roller 1. The thermal head 8 is pivotally supported so as to be brought into contact with and separated from the sheet 5.

Further, a reflective first optical sensor 6 for detecting the leading edge of the recording paper 2 is provided on the guide surface 3a on the downstream side in the rotation direction indicated by the arrow R1 of the platen roller 1, and is opposed to the leading edge of the thermal head 8. At the top of the fixed guide 3, there is a reflective type to detect a detection area for identifying the ink area of the three colors (yellow, magenta, and cyan) applied to the ink sheet 5, for example, a black mark. A second light sensor 10 is provided.

The ink sheet 5 is moved by an arrow R2 by a driving means (not shown).
direction until the second optical sensor 10 detects the black mark. As a result, the yellow ink area is first colored by the heating element 9 provided on the thermal head 8.
is conveyed to the vicinity of the printing position where it is pressed onto the recording paper 2. On the other hand, after the first optical sensor 6 detects the leading edge of the recording paper 2 being conveyed while being pinched by the platen roller 1 and the pressure roller 4, the recording paper 2 is rotated by a predetermined angle by rotating the platen roller 1. , and is transported to the printing position. Thereafter, the thermal gutter 8 is brought into pressure contact with the recording paper 2, and a power source (not shown) starts energizing the heating element 9, and printing is performed.

In the printing operation, as the platen roller 1 rotates in the direction of the arrow R1, printing is repeated for each line, and in the first rotation, printing regarding yellow ink is performed. Thereafter, printing with magenta ink and cyan ink is performed in the same manner. In this way, a plurality of colors can be expressed by making the three colors of ink, yellow, magenta, and cyan more important.

Problems to be Solved by the Invention In the printing apparatus as described above, as shown in No. 411Z, there is a gap between the end 3b of the fixed guide 3 and the protective cover 7, and between the tip 7a of the protective cover 7 and the heating element substrate. There is a step between it and 8a. For this reason, the recording paper 2 is made of sturdy and hard single sheet paper.
When using the recording paper 2, as shown by the imaginary line in FIG. 4, the rear end 2a of the recording paper 2 is raised by the step, and vR impact force is applied to the thermal head 8 during printing operation.
This causes a problem in that the state of the thermal head 8 in contact with the recording paper 2 changes, resulting in horizontal streak-like density unevenness.

SUMMARY OF THE INVENTION An object of the present invention is to provide a printing device that solves the above-mentioned technical problems and significantly improves printing quality.

Means for Solving the Problems The present invention provides a rotating roller on which a cut sheet of recording paper is stretched and driven to rotate in a predetermined direction, and a printing means arranged at a desired printing position along the circumferential direction of the rotating roller. and a rotary roller provided surrounding the rotating roller from a predetermined position on the downstream side in the rotational direction to a position spaced apart from the upstream side in the rotational direction of the printing means, and recording on the inner circumferential surface. a guide member that guides the paper; a flexible guide member that extends between the downstream end of the guide member in the rotational direction and the printing means, is continuous with the inner peripheral surface of the guide member, and is provided to surround the rotating roller; This is a printing device characterized by including:

According to the present invention, the printing means is arranged at a desired printing position along the circumferential direction of the rotating roller, which is rotated in a predetermined direction on which a cut sheet of recording paper is stretched. Ru. Further, a guide member that is provided surrounding the rotating roller and that guides the recording paper on the inner circumferential surface moves from a predetermined position on the downstream side in the rotational direction in relation to the printing means in the rotational direction of the printing means. are provided over positions spaced upstream from each other. Furthermore, a flexible guide member provided surrounding the rotating roller is provided so as to extend between the downstream end of the guide member in the rotational direction and the printing means, and to be continuous with the inner circumferential surface of the guide member. .

Therefore, by rotating the rotating roller in a predetermined direction, the recording paper in the form of a sheet stretched over the rotating roller is guided by the guide member and the flexible guide member and conveyed to the printing position, and the printing device prints the paper. It will be done.

At this time, since the trailing edge of the recording paper is guided by the flexible guide member from the guide member to the vicinity of the printing position of the printing means, the recording paper is This prevents the rear end from flipping up and applying impact force to the printing means, and the positional relationship of the printing means with respect to the recording paper can always be maintained in a constant state! As a result, the printing condition of the printing means can be maintained uniformly, and the quality of the printing can be significantly improved.

Embodiment FIG. 1 is a side view of a thermal transfer shadow printing apparatus which is an embodiment of the present invention. Guide surface 23 for guiding the recording paper 22
a fixed guide 2 having a plurality of pressing rollers 24 for pressing the recording paper 22 against the platen roller 21;
3 is provided surrounding the platen roller 21 on which the recording paper 22 is stretched. The thermal head 28 includes a protective cover 27 and a heating element substrate 28a, and a plurality of heating elements 29 are connected to the platen roller 2 on the heating element substrate 28a.
They are arranged in one row in the axial direction of 1. The flexible guide member 31 has one end attached to the opposite side of the fixed guide 23 from the platen roller 21 by a fixing plate 32 and a swash 33, and the other end has a heating element 29 mounted on the recording paper 22. The printing position to be pressed surrounds one Latin roller 21 up to a point. The fixed guide 23 also includes a first optical sensor 2, which will be described later.
6 is provided.

2I is an exploded perspective view showing the configuration related to the flexible guide member 31. The fixed guides 23 are arranged near both ends of the platen roller 21 in the axial direction. A plurality of shafts 34 are inserted, and pressure rollers 24 are provided at both ends of these shafts 34.The pressure rollers 24 are pressed against the outer circumferential surface of the platen roller 21 by a plate, not shown, or the like.

An insertion hole 35 is formed at one end of the flexible guide member 31 for inserting the T-shaped screw 33 therethrough. Fixing plate 3 with screw 33
The flexible guide member 31 is fixed by being inserted through the insertion hole 2 and the insertion hole 35 of the flexible guide member 31 and screwed onto the fixed guide 23. At this time, the L-shaped fixed plate 3
2 by pushing the flexible guide member 31 onto the top 23 (of the fixed guide 23).
1 is disposed so as to be continuous with the guide surface 23a.

For the flexible guide member 31, a Teflon sheet with a thickness of 0.2 mm is selected, for example. The material of the flexible guide member 31 may be resin or *g, and the thickness can be changed as appropriate depending on the material.

FIG. 3 is a side view showing the configuration of a thermal transfer type printing device in which a flexible guide member 31 is housed. It has a grating roller 21 rotated in the direction of arrow A by a means, a concentric guide surface 23a with a larger diameter than the platen roller 21, and a recording paper 22.
A fixed guide 23 having a plurality of pressure contact rollers 24 that press the paper toward the platen roller 21 and a Q heating element 29 are arranged in a row and are applied to the recording paper 22 on one platen roller 21 via an ink sheet 25. The thermal head 28 is pivotally supported so as to be brought into contact with and separated from each other. Fixed guide 2
3 is provided from a predetermined position on the downstream side in the rotation direction indicated by arrow A in relation to the thermal head 28 to a position spaced apart from a predetermined position on the upstream side in the rotation direction of the thermal head 28 .

Further, a reflective first optical sensor 26 for detecting the leading edge of the recording paper 22 is provided on the guide surface 23 a of the platen roller 21 on the downstream side in the rotational direction indicated by the arrow A.
On the upper part of the fixed guide 23 facing the tip of the ink sheet 25, there is a limb detection part, for example, a black mark, for identifying the ink area of the three colors (yellow, magenta, cyan) applied to the ink sheet 25. A reflective second optical sensor 30 is provided for detection.

The ink sheet 25 is distributed between a supply reel 36 and a take-up reel 37.
The wire is wound around the wire and is conveyed in the direction of arrow B by a driving means (not shown). By conveying the ink sheet 25 until the second optical sensor 1730 detects the black mark, the yellow ink area is first brought to the printing position where the heating element 29 provided in the thermal head 28 is pressed onto the recording paper 22. transported. On the other hand, after the first optical sensor 26 detects the leading edge of the recording paper 22 which is being pinched between the grating roller 21 and the pressure roller 24 and being guided and conveyed by the guide surface 23 Zt of the fixed guide 23, the platen roller 21 By rotating the recording paper 22 by a predetermined angle, the recording paper 22 is conveyed to the printing position. After that, the thermal head 28 is pressed onto the recording paper 22, and a power supply (not shown) starts energizing the heating element 29, and a printing operation is performed.

In the printing operation, printing is repeated line by line as the platen roller 21 rotates in the direction of arrow A, and printing with yellow ink is performed in the first rotation. Print information from a print information generating means 41 realized by a video tape recorder or the like is given to a print control means 43 via a control means 42 that controls the entire printing apparatus. Print control means 4
Reference numeral 3 controls the energization time of the heating element 29 based on the print information, and also controls the drive means for the platen roller 21 and the ink sheet 25.

Referring to FIGS. 1 and 3 described above, the printing operation on the recording paper 22 is performed sequentially from the leading edge 22b of the recording paper 22, and the trailing edge 22a of the recording paper 22 touches the end 23b of the fixed guide 23. Once passed, the rear end 22EL is subsequently guided by the visibility guide member 31. Flexible guide member 3
1 is provided so as to be continuous with the guide surface 23a of the fixed guide 23, so that the rear end 22a does not jump up due to a step as in the conventional case, and smoothly moves to the heating element substrate 28a.
You will be guided to

As described above, according to this embodiment, by providing the flexible guide member 31, it is possible to prevent the trailing edge 22a of the recording paper 22 from jumping up. It is possible to prevent impact force from being applied to the thermal head 28 due to the rear end 22a jumping up.

Therefore, it becomes possible to stabilize the pressure of the thermal head 28 against the recording paper 22, and it is possible to maintain a uniform printing condition, thereby significantly improving the printing quality.

Further, the present invention may be implemented in a printing device using thermal recording paper or a printing device using an inkjet printing head.

Effects of the Invention As described above, according to the present invention, by providing a flexible guide member, when using a piece of recording paper that is strong and hard, the impact force caused by the rear end of the recording paper jumping up can be reduced. is prevented from being applied to the printing means, and the positional relationship of the printing means with respect to the recording paper can always be maintained in a constant state. As a result, the printing condition can be maintained uniformly, and the printing quality can be significantly improved.

[Brief explanation of the drawing]

FIG. 1 is a side view showing one embodiment of the present invention, FIG. 2 is an exploded perspective view showing the structure related to the flexible guide member 31, and FIG.
The figure is a side view showing the basic structure of a thermal transfer printing device provided with a flexible guide member 31, and FIG. 4 is a side view showing the tII precept of a conventional thermal transfer printing device.

Claims (1)

[Scope of Claims] A rotating roller on which a cut sheet of recording paper is stretched and driven to rotate in a predetermined direction; a printing means disposed at a desired printing position along the circumferential direction of the rotating roller; and a printing means. Relatedly, a guide is provided surrounding the rotating roller from a predetermined position on the downstream side in the rotational direction to a position spaced apart from the upstream side in the rotational direction of the printing means, and guides the recording paper on the inner circumferential surface. and a flexible guide member that extends between the rotational direction downstream end of the guide member and the printing means, is continuous with the inner circumferential surface of the guide member, and is provided to surround the rotating roller. A printing device.