JPH0664332B2 - Image forming solvent coating method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image in an image recording apparatus for transferring an image recorded on a photothermographic material to an image receiving material in the presence of an image forming solvent to obtain an image. The present invention relates to a forming solvent coating method.

[Prior Art] As an image recording apparatus for obtaining a color image using a photothermographic material, as shown in JP-A-59-75247, a photothermographic material is exposed to an image at the exposure section and then developed at the development section. ,
It is known to transfer an image after heat development to an image receiving material.

Another device using a photothermographic material is disclosed in Japanese Patent Application No. 61-124407 filed by the present applicant. In this device, in order to improve the transfer efficiency before the photosensitive material or the image receiving material is sent to the transfer section,
A transfer aid (image forming solvent) such as water is applied in advance.

To apply the image forming solvent, a part of the coating roller is immersed in the water tank, and the water in the water tank is taken out by the rotation of the coating roller to apply it to the photosensitive material or the image receiving material being conveyed.

In this case, if the radius of the coating roller is not uniform, the photosensitive material or the image receiving material is unevenly coated with each revolution of the coating roller, which causes unevenness in image transfer. In particular, this coating unevenness occurs when the axis of the coating roller is deviated, and even when the coating rollers are aligned and the radius error of the coating roller is about 2 to 3 μm.

In view of the above facts, an object of the present invention is to obtain a solvent coating method for image formation which can reduce image transfer unevenness even when the radius of the coating roller is not constant.

[Outline and Action of the Invention] The present invention is a method for applying a solvent for image formation in an image recording apparatus, which obtains an image by transferring an image recorded on a photothermographic material to an image receiving material in the presence of an image forming solvent. Then, the rotation speed of the coating roller that applies the image forming solvent to the photothermographic material or the image receiving material is R (rps), and the feeding speed of the photothermographic material or the image receiving material is V (mm / s).
P (mm) = coating pitch P defined by V / R is 1.5 mm
The feature is that the image forming solvent is applied by setting as follows.

The present inventor has investigated the relationship between the unevenness in coating and the variation in the image density that occur every one rotation of the coating roller. The fact that an image can be obtained was investigated. As a result, in the present invention, the coating pitch by the coating roller is controlled to be 1.5 mm or less, which makes it possible to eliminate coating unevenness and perform good image transfer.

The photothermographic material in the present invention is a material in which a movable dye is released on an image by heating, and the movable dye is transferred to an image receiving material (dye fixing material) having a mordant with a solvent such as water. , Those which are transferred to the image receiving material by a high boiling point organic solvent, those which are transferred to the image receiving material by the hydrophilic thermal solvent contained in the image receiving material, or the movable dyes are heat diffusible or sublimable and are supported. Those that are transferred to a dye receiving material such as the body are known, and specifically, U.S. Pat. Nos. 4,463,079, 44,748,67, and 44,
No. 78927, No. 4507380, No. 4500626, No. 4843914
No. 58-149046, No. 59-154445, No. 59-1650.
54, 59-180548, 59-168439, 59-174832
No. 59-174833, No. 59-174834, No. 59-174835, and the like.

Further, in the present invention, the image forming solvent is a solvent required for image formation, and is, for example, water, a low boiling point organic solvent (alcohol, ketone, amide, etc.) or a surface active agent for these solvents. Agents, development accelerators, development terminators, and various additives are included.

[Embodiment] An image recording apparatus according to an embodiment of the present invention will be described below.

FIG. 2 shows a schematic configuration diagram of an image recording apparatus according to an embodiment of the present invention. In the image recording apparatus 10, a roll-shaped photothermographic material 16 is housed in a magazine 14 housed in a machine base 12. The photosensitive material 16 is pulled out from the outer periphery of the cutter 18
After being cut into a predetermined length by, the tape is wound around the outer circumference of the rotary drum 20. An exposure head 22 is arranged corresponding to the outer circumference of the rotary drum 20, and the rotary drum 20 is rotated in the direction of arrow A to wind the photosensitive material.
Expose the image to 16.

The exposed photosensitive material 16 is peeled from the rotary drum 20 by the scraper 24 by the reverse rotation of the rotary drum 20, and after the water is applied by the water application section 26 as the image forming melt, heat is applied inside the heating section. It is sent to the developing and transferring section 28.

On the other hand, the uppermost layer of the plurality of image receiving materials 32 accommodated in the tray 30 is sent to the heat development transfer section 28.

Conveying rollers 34 and 36 that are in close contact with each other are provided at the inlet of the heat development transfer section 28 so that the photosensitive material 16 and the image receiving material 32 are brought into close contact with each other and then fed to the conveying rollers 38 and 40 at the outlets. Conveying rollers 42 and 44 are provided at the intermediate portion, and the photosensitive material 16 is closely attached and is fed from the conveying rollers 34 and 36.
And the image receiving material 32 are sent to the conveying rollers 38 and 40. Each transport roller is configured to receive the rotational force by transmitting the driving force of a motor (not shown).

Each transport roller has a heater 46 disposed on the opposite side of the transport path between the photosensitive material 16 and the image receiving material 32, and is heated to a predetermined temperature by a heating element composed of an electric heating element.

A stripping means 48 is arranged downstream of the heat development transfer section 28 to separate the photosensitive material 16 sent from the heat development transfer section 28 into a waste photosensitive material storage box 50 and the image receiving material 32 into a drying device 52. It is designed to be sent out. The image receiving material 32 is a drying device.
After being dried at 52, it is delivered onto an ejection tray 54 formed on the top of the machine base 12.

As shown in FIG. 1, a pair of conveying rollers 60 and 62 for sandwiching the conveyed photosensitive material 16 are arranged in the water applying section 26,
A pair of transport rollers is provided downstream of these transport rollers 60 and 62.
64 and 66 are arranged so as to sandwich and convey the photosensitive material 16.

These rollers receive the driving force of the motor 67 and the photosensitive material 16
Is sent to the heat development transfer portion 28 in the direction of arrow B. Further, guide plates 68 and 70 are provided between these conveying rollers so as to correspond to both side ends of the conveyed photosensitive material 16, and the photosensitive material 16 is conveyed from between the conveying rollers 60 and 62 to the conveying roller 6.
It is supposed to guide you between 4 and 66.

Between the conveying rollers 62 and 66, a coating roller 72 as a coating member corresponds to the central portion on the emulsion surface side of the photosensitive material 16. The shaft 74 of the coating roller 72 is connected to a motor 76, and the coating roller 72 is driven by the motor by an arrow C.
It is designed to rotate in the direction. The motor 76 is controlled by the controller 78 together with the motor 67.

A part of the coating roller 72 is immersed in a main tank 82 filled with water 80 which is an image forming solvent, and the water 80 is taken out on the peripheral surface when rotating. The water 80 carried out by the coating roller 72 forms a bead 80A between it and the photosensitive material 16, and in this state, water is transferred to the back surface of the photosensitive material 16 in accordance with the conveyance of the photosensitive material 16. Is to be applied.

A main pipe 82 filled with water 80 supplies a supply pipe 84 for supplying the water 80 and a discharge pipe 86 for discharging the water 80 in the main tank 82.
And are attached. Further, an overflow pipe 88 is attached to the main tank 82 for discharging an excess of the water 80 with which the main tank 82 is filled.

A sensor 90 for detecting the tip of the photothermographic material 16 is provided on the upstream side of the transport roller 62.

The operation of this embodiment will be described below.

When the photosensitive material 16 pulled out from the magazine 14 is wound around the rotary drum 20 after being cut by the cutter 18,
The rotary drum 20 rotates at a high speed, and the exposure head 22 exposes an image.

After exposure, the photosensitive material 16 is peeled off by the scraper 24, coated with water by the water coating section 26, and sent to the heat development transfer section 28.

On the other hand, the image receiving material 32 in the tray 30 is sent from the uppermost layer to the heat source image transferring section 28 and is brought into close contact with the photosensitive material 16.

The light-sensitive material 16 and the image-receiving material 32 that have been brought into close contact with each other are conveyed rollers.
It is sent to the transport rollers 42 and 44 through 34 and 36. Further, it is sent out between the conveying rollers 42, 44 through the conveying rollers 38, 40. In this way, the pairs of transport rollers are heaters.
Since it is heated by 46, the photosensitive material 16 and the image receiving material 32
Is immediately brought to a predetermined temperature, and the image recorded on the photosensitive material 16 is thermally developed and transferred to the image receiving material 32 by heat.

After transfer, the photosensitive material 16 and the image receiving material 32 are separated by the peeling means 48.
When the photosensitive material 16 is removed, the photosensitive material 16 is transferred to the waste photosensitive material transport rack 60
Is guided to the waste photosensitive material storage box 50, and the image receiving material 32 is taken out to the taking-out tray 54 through the drying device 52.

Next, the application state of the water 80 in the water application section 26 will be described.

As shown in FIG. 1, the conveyance roller 60 is driven by the motor 67,
Water 80 is applied to the emulsion surface of the photothermographic material 16 which is nipped and carried by 62 and the carrying rollers 64 and 66 by the applying roller 72.

However, when the radius of the coating roller 72 is not uniform due to the misalignment of the shaft center of the shaft 74 or the like, coating unevenness occurs on the photothermographic material 16 every one rotation of the coating roller 72. The difference between the thick coating portion and the thin coating portion (coating unevenness width) in coating unevenness that occurs every one rotation of the coating roller 72 is determined by the number of rotations of the coating roller 72 and the transport speed of the photothermographic material 16, that is, the coating pitch. One point on the roller changes at intervals of a plurality of points that contact the surface of the photothermographic material 16.

This coating pitch P is It is represented by.

FIG. 3 is a diagram showing the relationship between the coating unevenness width and the coating pitch. The coating unevenness width is a value converted from the image density after the image transfer in the heat development transfer section 28. As is clear from FIG. 3, the coating unevenness width is 1.5 mm for the coating pitch P.
It sharply drops below, and the control device 78 controls the rotation of the motors 67 and 76 so that the coating pitch becomes 1.5 mm or less, whereby the variation in the image density can be significantly reduced.

Specifically, when the feed speed V _P of the photosensitive material 16 by the motor 67 is determined, the rotation speed N _R of the coating roller is (V _P / 1.
5) The control device 78 may drive and control the motor 76 with the above predetermined values. This procedure is shown in FIG.

As a result, when the present embodiment is not adopted, it is necessary to suppress the radius difference of the coating roller, that is, the run length to 2 to 3 μm or less. On the other hand, even if the radius difference of the coating roller is about 80 μm, this coating It has become possible to extremely reduce variations in image density due to unevenness.

Although the above embodiment has been described with respect to the case where the image forming solvent is applied to the photothermographic material 16, it can be similarly applied to the case where the image forming solvent is applied to the image receiving material 32.

EFFECTS OF THE INVENTION Since the present invention is configured as described above, it has an excellent effect that uneven transfer image can be reduced by eliminating uneven application of the image forming solvent regardless of the radius difference of the applying roller.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a water application section of an image recording apparatus to which the present invention is applied, FIG. 2 is a vertical sectional view of the image recording apparatus, and FIG.
FIG. 4 is a diagram showing the relationship between the coating unevenness by the coating roller and the coating unevenness width, and FIG. 4 is a flow chart showing the control of this embodiment. 10 ... Image recording device, 16 ... Photothermographic material, 26 ... Water application part, 28 ... Heat development transfer part, 32 ... Image receiving material, 67 ... Motor, 72 ... Application roller, 76 ... Motor, 78 ... control device, 80 ... water.

Claims (1)

[Claims] 1. A method for applying a solvent for image formation in an image recording apparatus, wherein an image recorded on a photothermographic material is transferred to an image receiving material in the presence of an image forming solvent to obtain an image. P (mm) = V /, where R (rps) is the number of rotations of the coating roller that applies the image forming solvent to the material or the image receiving material, and V (mm / s) is the feed speed of the photothermographic material or the image receiving material. The coating pitch P defined by R is 1.
An image forming solvent coating method, which comprises setting the thickness to 5 mm or less and applying an image forming solvent.