JPS60965A - Picture recorder - Google Patents

Abstract

PURPOSE:To provide the titled recorder of small size, at a low cost, capable of recording good quality plural colors picture, by a method wherein an electrostatic recorder and a heat sensitive transfer recorder are linearly arranged on the carrying path of common electrostatic recording paper, and different color picture is recorded on the common electrostatic recording paper to respective recorders. CONSTITUTION:The two color picture is recorded by using the picture recorder consisting of the electrostatic recorder 23 having the electrostatic recording head 24, developing device 26 and fixing device 27 provided opposing to the carrying path of electrostatic recording paper 20 and of the heat transfer recorder 28 consisting of the heat sensitive recording head 29 provided opposing to this carrying path and the supply roller 32 and winding roller 33 as the measure travelling the heat sensitive transfer paper 31 between this heat sensitive recording head 29 and the carrying path. At first, black picture signal is supplied from an input terminal to an electrostatic recording head 24 and the latent image of black color picture is formed on the electrostatic recording paper 20. After developing and fixing it, red color picture signal is applied to the heat sensitive recording head 29 from input terminal 36 and the ink of heat sensitive transfer paper 31 is transferred to the electrostatic recording paper 20.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an image recording apparatus for recording images of at least two colors. FIG. 2 is a schematic side view showing an example of a recording device. This conventional example includes an electrostatic recording device 1a, a platen 211. A first electrostatic recording device consisting of a developing device 3a and a fixing device 4a, an electrostatic recording throat 1b, a platen 2b,
A second electrostatic recording device consisting of a developing device 3b and a fixing device 4b is arranged in series on the conveyance path of the electrostatic recording paper 6, and each electrostatic recording device prints a different color on the electrostatic recording paper 6. It is configured to electrostatically record images.

This conventional example has the advantage of being able to record high-resolution images even in colors that are out of b, but on the other hand, it requires two sets of complicated and expensive electrostatic recording devices, making the device complicated and large. There are problems in that it is difficult to formulate and expensive. This problem becomes even more pronounced when three or more recording colors are used.

A possible solution to this problem is to switch the voltage applied to the electrostatic recording head between positive and negative depending on the recording color, and to use two colors of toner with different charging polarities for development. .

However, in order to selectively apply positive and negative electric fields to the electrostatic recording head, another problem arises in that the head drive circuit becomes complicated.

Further, two-color toners having different charging polarities have a problem in that the toners may combine with each other, resulting in a lack of stability in recording operation. Furthermore, a latent image of opposite polarity is formed due to the undershoot of the electric field occurring at the boundary of the image, and toner of a color that should not be recorded adheres to the latent image, resulting in a problem that the quality of the recorded image is likely to deteriorate b.

FIG. 2 is a schematic side view showing another example of a conventional two-color image recording apparatus. In this figure, 6 is a thermal recording head, and 7 is a thermal recording head.
8 is a platen, and 8 is a thermal recording paper. This thermal recording paper 8
This has two color formers with different color forming temperatures, and the color density characteristics are shown in FIG. 9 and 10 are input terminals for image signals, and 11 is an input terminal 9 and 1o for the thermal recording head 6.
This is a switch that connects to the

To the input terminal 9, an image signal is inputted to the thermosensitive recording medium to generate heat up to the coloring temperature of the coloring agent of the color heating element iA of mud. The other input terminal 10 receives an image signal that causes the heating element to generate heat up to the heating temperature of the B color forming agent. Therefore, by switching the switch 11 to the input terminal 9 side to record in color A, and then switching to the input terminal 10 side to record in color B, it is possible to record a two-color image.

This conventional example allows the device to be made smaller, but when recording colors with high coloring temperatures, it is necessary to apply several times the normal energy to the thermal recording head, which shortens the life of the thermal recording head. There is a problem with becoming. Another problem is that the quality of the image is poor because colors with lower coloring temperatures appear at the boundaries of images of colors with higher coloring temperatures.

It is possible to solve this problem by changing the two-color thermal ink sheet to record a two-color image using a special thermal transfer method. However, since thermal transfer recording generally has low resolution, it is possible to There is a problem that images cannot be obtained.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned conventional problems, and aims to provide a compact, inexpensive, and highly reliable image recording apparatus that can record multi-color images of sufficiently good quality.

Structure of the Invention In the present invention, an electrostatic recording device and a thermal transfer recording device are arranged in series on a common electrostatic recording paper transport path, and each device records images of different colors on the common electrostatic recording paper. This configuration aims to achieve the above object.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 4 is a schematic side view of a two-color image recording apparatus according to an embodiment of the present invention. In this figure, reference numeral 20 denotes an electrostatic recording paper, which is moved along the conveyance path by an arrow 22 by a feed roller 21.
It is transported in the direction of. 23 is an electrostatic recording device for recording the entire black image on electrostatic recording paper 2o by a well-known electrostatic recording process;
It consists of a developing device 26 and a fixing device 27. 28 is a red image transferred to electrostatic recording paper 2 by a known thermal transfer process.
This is a thermal transfer recording device for recording on a thermal recording board 29, a platen 30. and a supply roll 32 and a take-up roll 33 of thermal transfer paper 31 coated with red thermal ink or sublimable dye. In the figure, the thermal transfer paper 31 is separated from the electrostatic recording paper 2o, but in reality it is in close contact with the electrostatic recording paper 2o directly below the thermal recording head 29. Further, the take-up roll 33 is given a weak rotational force in the direction of arrow 34, and the supply roll 32vrc is given a weak rotational force in the direction of arrow 34.
A weak braking force is applied to control the rotation in direction 6. Therefore, as the electrostatic recording paper 20 is transported,
The thermal transfer paper 2o is fed out from the supply roll 32, passes directly under the thermal head 29, and is wound onto a take-up roll 34.

To explain the recording operation, while conveying the electrostatic recording paper 20 continuously or intermittently, a black image signal is supplied from the input terminal 35 to the electrostatic recording medium 24, and the latent image of the black image is transferred to the electrostatic recording paper. A red image signal is applied to the thermal recording head 29 from the input terminal 36 while taking timing with the recording operation of this black image. A red image is recorded by transferring the ink or sublimable dye from the thermal transfer paper 31 to the electrostatic recording paper 20. In this way, a two-color image of red and black is recorded on the electrostatic recording paper 20.

Image resolution will now be explained. Generally, the thermal transfer recording device 28 has lower image resolution than the electrostatic recording device 23. However, in general, when recording images of two or more colors, an image of the first color (here, black) is often used as the base image, and an image of the remaining color (here, red) is treated as an auxiliary image. For example, the main text of a document is recorded in black, and proofreading characters, notes, seal impressions, etc. are recorded in red. Therefore, if the first color image is recorded with the high-resolution electrostatic recording device 23,
Recorded images of substantially high quality can be obtained.

Note that if you want to obtain a two-color image based on red, you can also achieve high performance by changing the color of the toner used in the developing device 26 to red, and changing the color of the ink or dye on the thermal transfer paper 31 to black. A quality two-color recorded image is obtained.

FIG. 6 is a schematic side view showing a two-color image recording apparatus according to another embodiment of the present invention. In this figure, the same reference numerals as in FIG. 4 indicate equivalent parts.

In this embodiment, wasteful consumption of the thermal transfer paper 31 is prevented by retracting the platen 30i and stopping the running of the thermal transfer paper 31 during a period when image recording by thermal transfer is not performed. Different from the example. That is, the platen 30 is attached to a lever 39 that is rotated about a fulcrum 38 by a platen driving means 37 such as a solenoid, and an auxiliary roller 40'i5 is provided ahead of the platen 3o (to the right in the figure). A signal is supplied to the platen driving means 37 only during the period of thermal transfer recording of the red image, and the lever 39 is rotated upward by the platen driving means 37 to push up the platen 30i. In this state, the thermal transfer paper 31 is not pressed against the electrostatic recording paper 2o and travels together with the electrostatic recording paper 20. During a period in which a red image is not recorded, the signal to the input terminal 41 is cut off, thereby rotating the lens <-39 downward and retracting the platen 30i.

In this state, the electrostatic recording paper 2o runs at a position as shown by the broken line in the figure, so the running of the temperature-sensitive thermal transfer paper 310 is stopped.

In this embodiment, the platen 3o is moved, but the platen 3o is fixed and the thermal recording is performed instead.
It is clear that the running of the thermal transfer paper 31 can be controlled in the same way by moving the roller 9 up and down.

Further, in each of the above embodiments, the electrostatic recording device was placed in the first stage and the thermal transfer recording device was placed in the second stage; however, this order may be reversed.

Furthermore, it is clear that by providing two or more thermal transfer recording devices, it is possible to realize a complete image recording device capable of recording images in three or more colors.

Effects of the Invention As described above, since the present invention combines an electrostatic recording device and a thermal transfer recording device, the following effects can be obtained.

(1) A thermal transfer recording device is cheaper than an electrostatic recording device and can be easily miniaturized, so it is a combination of two or more electrostatic recording devices.It is a smaller and cheaper image recording device than the conventional example. (2) The base image that determines the quality of the recorded image can be recorded using a high-resolution electrostatic recording device, and the polarity of the recording electric field can be switched using two-color toner. The base image can be recorded in high quality without any need, and therefore a two-color or multicolor high-quality image can be obtained.

(3) A highly reliable image recording apparatus can be realized without the problem of lifespan of thermal recording, which occurs when thermal recording paper having two or more color formers is used.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view of a conventional image recording apparatus, FIG. 2 is a schematic side view of another conventional example, FIG. 3 is a characteristic diagram showing the color density characteristics of thermal recording paper, and FIG. 4 is a diagram showing the color density characteristics of thermal recording paper. FIG. 5 is a schematic side view of an image recording apparatus according to another embodiment of the present invention. 20... Electrostatic recording paper, 23... Electrostatic recording device, 24°°゛°° To electrostatic recording, 26...
°・°°Platen, 26...Developer, 27...
. . . Fixing device, 28 . . . Thermal transfer recording device,
29...To thermal recording, 3o...Platen, 31...Thermal transfer paper, 32...
Supply roll, 33…°°C take-up roll. Name of agent: Patent attorney Toshio Nakao and one other person.

Claims (1)

[Claims] An electrostatic recording device having an electrostatic recording device, a developing device, and a fixing device provided opposite to one general transport path of electrostatic recording paper, and a thermosensitive recording device provided opposite to the transport path. An image recording apparatus comprising a heat-sensitive transfer recording device having means for running a heat-sensitive transfer paper between the heat-sensitive recording head and the conveyance path.