JPH0369930A - Image forming device - Google Patents

Abstract

PURPOSE:To accurately form or read an image by adjusting the rigidity of each member of an image forming part or an image reading part and causing the same vibration to all the members. CONSTITUTION:By taking the supporting parts of a pulley 304 for driving an exposing head 22 as A and B and the supporting parts of both ends of a rotating drum 20 is C and D respectively, internal vibration and external vibration are transmitted in a path like A-D-C-B-A. When any of respective frequencies is larger than the natural frequency of the exposing head 22 to the rotating drum 20, the transmission path to which a high-rigidity reinforcing member, for example, is added is provided or a member corresponding to the transmission path is constituted of a high-rigidity material in order to enhance the rigidity of the transmission path. Thus, the exposing head 22 and the rotating drum 20 are vibrated in the same way and a relative distance between the is not changed. The deviation of exposure caused by the effect of the vibration is prevented and an accurate image having uniform density is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image forming apparatus having an image forming section or an image reading section, and particularly relates to anti-vibration measures for the image forming apparatus.

[Conventional technology]

Heat-developable photosensitive materials are well known as image-forming materials used in image-forming devices, and the heat-developable photosensitive materials and their processes are described, for example, in Basic Non-Silver Salt Photography Edition of Photographic Engineering (1988).
Pages 242 to 255 of Corona Publishing (2003), 40 pages of video information published in April 1978, Neblets Handbook
Of Photography and Reprography (
Neblett's Handbook of Pho
tography and reprography)
7th edition (7th Bd,) Van Nostrand Reinhold Cumber 1--(Van No5tra
nd Re1nhold Company) 32-3
It is described on page 3.

In addition, regarding the method of obtaining a color image by heat development, a mobile dye is released in an image form by heating, and this mobile dye is transferred to a dye fixing material (an image receiving material) having a mordant using a solvent such as water. ), transfer to a dye fixing material using a high boiling point organic solvent, transfer to a dye fixing material using a hydrophilic thermal solvent built into the dye fixing material, and methods in which mobile dyes are thermally diffusible or sublimable. A method of transferring the dye to a dye-receiving material such as a support has been proposed.

As an apparatus for carrying out this type of image forming method, for example, as disclosed in Japanese Patent Laid-Open No. 59-75247, an exposure head is used in an exposure section to expose a color image onto a heat-developable photosensitive material. Afterwards, an image-forming solvent such as water is applied to the heat-developable photosensitive material using a roller, and this is sent to a heat development section.The image-receiving material is brought into close contact with the heat-developable photosensitive material after heat development, and then sent to the transfer section. 2. Description of the Related Art Image forming apparatuses have been proposed in which an image is thermally transferred to an image receiving material in a transfer section.

[Problem to be solved by the invention]

Scanning exposure using an exposure head requires high exposure accuracy, but vibrations inside and outside the exposure section are transmitted to the exposure head and the photosensitive material, causing different vibrations in the exposure head and the photosensitive material.

For example, sources of these vibrations include a motor that drives the exposure head, a motor that conveys the photosensitive material, and a solenoid that moves the exposure head toward and away from the photosensitive material. and,
When these vibrations are transmitted to the exposure head and the photosensitive material, accurate exposure is not performed and density unevenness occurs in the formed image.

Although external vibrations can be prevented to some extent by a spring damper, when the image forming apparatus is formed into units, it is difficult to align each unit.

In addition, internal vibrations can be reduced by using a high-precision sensor to detect vibrations, a multiphase brushless morph, etc. as a driving means, and detecting vibrations and controlling the driving means. Processing becomes complicated and control is not easy.

Further, similarly to the image forming section, accurate reading is not performed in the image reading section due to the influence of vibrations, and therefore, the image finally obtained through subsequent image forming processing is not accurate.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and to provide an image forming apparatus that can prevent the influence of internal vibrations and external vibrations in an image forming section or an image reading section and perform accurate image formation and reading. It is about providing.

[Means and Effects for Solving the Problems] The above object of the present invention is to reduce internal vibrations and external vibrations in the image forming section or the reading section in an image forming apparatus having vibration sources inside and outside the image forming section or the reading section. This is achieved by an image forming apparatus configured by adjusting the rigidity of the constituent members of the image forming section or the reading section so that the natural frequency of the image forming section or the reading section is higher than each frequency of the spectrum.

In other words, the rigidity of each member of the image forming section or the reading section is adjusted so that each frequency of the internal vibration spectrum and the external vibration spectrum in the image forming section or the reading section is within a range smaller than the natural frequency of the image forming section or the reading section. By adjusting and configuring the structure, even if internal vibrations and external vibrations occur, all members generate the same vibration, so the relative positions of each member do not substantially change. Therefore, image formation or reading can be performed accurately.

To adjust the stiffness of each member, select the material that makes up the member to have the appropriate stiffness, or add other members or remove part of the member so that each member has the appropriate stiffness. delete.

Detection of internal vibration spectrum and external vibration spectrum is
A vibrator applies vibration to the measurement target, and an accelerometer measures the displacement.
This is done by measuring velocity or acceleration.

Specifically, the natural frequency of the image forming section is the natural frequency of the recording means with respect to the recording material support, and is measured by an accelerometer equipped with a measuring element on the recording material support and the recording means.

Further, the natural frequency of the image reading section is specifically the natural frequency of the reading means with respect to the document support, and is measured by an accelerometer provided with a probe on the document support and the reading means.

The internal vibration spectrum and external vibration spectrum in the image forming section are shown, for example, as shown in FIG. Figure 3 (
a) represents the internal vibration spectrum, and FIG. 3(b) represents the external vibration spectrum, fl, f2, f3, f4, and f5 represent the vibration frequencies of each member.

For example, the vibration transfer function (rigidity) in the image forming section is
When expressed as shown, the natural frequency is fo. This natural frequency fh is the frequency of each member fl, f2, f5,
If f4,f is larger, all members will vibrate the same and the relative position of each member will not change substantially. Therefore, internal vibrations and external vibrations do not adversely affect image formation.

In addition, the vibration frequencies f, , f, , f5, fl, f5 of each of the four members
There is a higher harmonic vibration, and the higher harmonic frequency is the natural frequency f. The natural frequency f is very small compared to f. , higher harmonic frequencies will not adversely affect image formation. Note that the shaded area in the graph is a vibration region where external vibrations and internal vibrations are not allowed, and the vibration frequency and vibration acceleration of each member are set below the shaded area.

In the present invention, any image forming method may be used, such as a photosensitive recording method, a heat-sensitive recording method, a pressure-sensitive recording method, an inkjet method, and the like.

Image forming materials that can be used in the present invention include:
Examples include heat-developable photosensitive materials. Examples of the heat-developable light-sensitive material include heat-developable light-sensitive materials in which heat development and transfer are performed simultaneously. Regarding the above-mentioned heat-developable photosensitive materials, U.S. Pat.
No. 4゜478.927, No. 4.507,38
No. 0, No. 4.500.626, No. 4. 483.
No. 914, JP-A-58-149046, JP-A No. 58-1
No. 49047, No. 59-152440, No. 59-15
No. 4445, No. 59-165054, No. 59-180
No. 548, No. 59-168439, No. 59-1748
No. 32, No. 59-174833, No. 59-17483
No. 4, No. 59-174835, No. 61-232451
No. 62-65038, No. 62-253159,
No. 64-13546, European Patent Publication No. 210.660A
No. 2, No. 220.746A2, etc.

The above-mentioned heat-developable photosensitive material basically consists of photosensitive silver halide, a binder, a dye-providing compound, a reducing agent (
In some cases, the dye-donating substance also serves as a reducing agent), and if necessary, organic silver salts and other additives can be contained.

The heat-developable photosensitive material may be one that gives a negative image or one that gives a positive image when exposed to light. Direct positive emulsion as a silver halide emulsion (there are two types: a method that uses a nucleating agent and a method that uses light fogging) to provide a positive image.
Either a method using a dye-donating compound or a method using a dye-donating compound that emits a positively diffusible dye image can be adopted.

There are various methods for transferring diffusible dyes, such as transferring to a dye fixing layer using an image forming solvent such as water, transferring to a dye fixing layer using a high boiling point organic solvent, and transferring to a dye fixing layer using a hydrophilic thermal solvent. A method of transferring the dye to a dye fixing layer having a dye-receiving polymer using the thermal diffusivity or sublimation of a diffusible dye has been proposed.
It can be any of them.

In addition, as the image forming solvent used for the above diffusion transfer,
For example, there is water, and this water includes not only so-called pure water but also water in a widely customary sense. Alternatively, a mixed solvent of pure water and a low boiling point solvent such as methanol, DMF, acetone, or diisobutyl ketone may be used. Furthermore, a solution containing an image formation accelerator, an antifoggant, a development stopper, a hydrophilic heat solvent, etc. may also be used.

[Embodiment]

Hereinafter, one embodiment of the present invention will be described in detail based on the accompanying drawings.

FIG. 1 is a schematic diagram of an image forming apparatus according to an embodiment of the present invention.

A magazine 14 is disposed on the machine base 12 of the image forming apparatus 10, and a roll-shaped photothermographic material 16 is housed within the magazine 14.

The heat-developable photosensitive material 16 is pulled out from its outer periphery, cut into a predetermined length by a cutter 18, and then wound around the outer periphery of a rotating drum 20 in the six directions of arrows.

An exposure head 22 is disposed corresponding to the outer periphery of the rotating drum 20, and rotates the rotating drum 20 at high speed to expose an image onto the wound photothermographic material 16.

After exposure, the photothermographic material 16 is transferred by rotating the rotating drum 20 in reverse (
direction of arrow B), the scraper 24 rotates the rotating drum 20.
The sheet is peeled off from the substrate and further conveyed by a pair of conveying rollers 25 and 27. Conveyance roller pair 25.27
is rotated by a step motor (not shown) as a driving means.

A water application section 26 is provided between the pair of conveyance rollers 25 and the pair of conveyance rollers 27 on the conveyance path of the photothermographic material 16 . A coating roller 64 rotated by an AC motor (not shown) is disposed in the water coating section 26, and the photothermographic material 16 is transferred to the coating roller 64 while being conveyed.
Water is applied as an image-forming solvent by contacting with.

Heat-developable photosensitive material #J with added water! 16 is sent to a thermal development transfer section 28.

In the thermal development transfer section 28, a heating drum 34 and an endless pressure belt 36 serving as pressure contact means are arranged. Further, a halogen lamp 38 is disposed inside the heating drum 34, and the outer peripheral surface of the heating drum 34 is heated to about 90° C. by the halogen lamp 38.

The endless crimping belt 36 is wrapped around rollers 37, 39, 41.
．． 43, and its endless outer side is pressed against the outer peripheral surface of the heating drum 34. For winding, the roller 37 is rotated by a step motor (not shown), and along with this, the endless pressure belt 36 and the heating drum 3 are rotated.
The heat-developable photosensitive material 16 is sandwiched and conveyed between the photothermographic material 4 and the heat-developable photosensitive material 16 to be thermally developed.

A rubber bonding roller 48 is placed in the vicinity of the portion where the endless pressure belt 36 is wound around the roller 37 so as to be pressed against and in contact with the outer peripheral surface of the heating drum 34 . This bonding roller 48 is also rotated by a step motor (not shown).

The image receiving material 32 sent to the thermal development transfer section 28 is transferred by a bonding roller 48 disposed in contact with the outer circumferential surface of the heating drum 34 (between the bonding roller 48 and the outer circumferential surface of the heating drum 34). ) The heat-developable photosensitive material 16 is bonded to the heating drum 34 and the endless pressure belt 36.
It is designed to be supplied between.

The heat-developable photosensitive material 16 is a heat-developable transfer! At 28, when the image receiving material 32 is bonded to the image receiving material 32 and heated while being conveyed, the image is thermally developed and transferred to the image receiving material 32, so that an image is obtained on the image receiving material 32.

A peeling plate 49 is arranged on the side of the thermal development transfer section 28 . The peeling plate 49 has a distal end close to the outer circumferential surface of the heating drum 34, moves together with the heating drum 34, engages with the photothermographic material 16 located inside, and receives the image of the photothermographic material 16. The material 32 is peeled off from the outer periphery of the heating drum 34.

A pair of separation rollers 50 are disposed below the peeling plate 49 and correspond only to both ends of the image receiving material 32 in the width direction.
Furthermore, a conveyor belt 52 is wound around the separation roller 50. This conveyor belt 52 engages only at both ends of the image receiving material 32 in the width direction, and transfers the image receiving material 32 to the photothermographic material 1.
6 and is bent and transported.

The separated image-receiving material 32 is dried by a heater 54 and then sent onto a take-out tray 56 formed at the top of the machine stand 12.

On the other hand, the separated photothermographic material 16 is conveyed by a pair of conveying rollers 58 and sent to a waste photosensitive material storage box 59.

FIG. 2 is a schematic diagram of the exposure section.

The exposure section includes a rotating drum 20 that supports the photosensitive material 16;
An exposure head 22 equipped with a light emitting element is provided, and each of these is driven by a separate motor. Rotating drum 2
0 rotates at high speed (main scanning), and the exposure head 22 moves on the rotating drum 20 along the axial direction of the rotating drum 20 (sub-scanning).

The rotating drum 20 is rotatably supported by a side wall 202 of the exposure section, and the exposure head 22 is fixed to a belt 200 stretched around a pulley 304 supported by the side wall 202. Further, a guide bar 201 passes through the exposure head 22 and is movable along the axial direction of the rotating drum 20 by a motor (not shown).

External vibrations from driving means and the like in other processing sections are transmitted from the side wall 202 to the exposure head 22 and the rotating drum 20, and further transmitted from one of these to the other. Further, internal vibrations from motors, fans, solenoids, etc. in the exposure section are mutually transmitted from the rad 22 and the rotating drum 20 to the exposure section.

The natural frequency of the exposure head 22 and the frequency of each member relative to the rotating drum 20 can be determined by applying vibration to one of the members using an exciter, equipping the measuring member with an accelerometer measuring element, and measuring displacement, velocity, etc. using the accelerometer. Alternatively, the acceleration is measured and converted into a vibration frequency by referring to the vibration frequency generated by the vibrator.

To measure the natural frequency of the exposure head 22 with respect to the rotating drum 20, first, the vibrator 310 is attached to, for example, the sub-scanning drive motor 311, and the measuring element 313 of the accelerometer 312 is attached to the rotating drum 20.

Then, the vibration exciter 310 is operated, and the vibration of the rotating drum 20 is measured based on the frequency of the vibration exciter 310. Such measurements are also performed on the exposure head 22, and further vibration measurements are performed on all vibration transmission members from the exposure head 22 to the rotating drum 20.

Vibration measurements for each member provide the spectra of external and internal vibrations, and based on these respective frequencies,
Adjust the stiffness of the vibration transmission path.

In FIG. 2, a pulley 30 that drives the exposure head 22
The supporting parts of 4 are designated A and B, respectively, and the rotating drum 20
Assuming that the support parts at both ends of are C and D, respectively, internal vibrations and external vibrations are transmitted through the path A-D-C-B-.

Here, if either the external vibration frequency or the internal vibration frequency measured by the accelerometer 312 is larger than the natural frequency of the exposure head 22 with respect to the rotating drum 20, the transmission paths A-DSD-CSC-B, B- In order to increase the rigidity at A, for example, a highly rigid reinforcing member is added to the transmission path, or a member corresponding to the transmission path is made of a highly rigid material. As for the rotating drum 20, the preload spring 314 applies a preload that sufficiently exceeds the generated vibration force to the support portion.
0 and the support portion can be considered to be substantially the same member. By increasing the rigidity of the vibration transmission path so that the natural frequency of the exposure head 22 with respect to the rotating drum 20 is larger than each frequency of external vibration and internal vibration, the exposure head 22 and the rotating drum 20 vibrate in the same way and there is no change in their relative distances. Therefore, exposure deviation due to the influence of vibrations is prevented, and accurate images with uniform density can be formed.

〔Effect of the invention〕

According to the present invention, the image forming section or the reading section is configured such that each frequency of the internal vibration spectrum and the external vibration spectrum in the image forming section or the reading section is in a range smaller than the natural frequency of the image forming section or the reading section. By adjusting the rigidity of each member and configuring it, even if internal vibrations and external vibrations occur, all the members generate the same vibration, so the relative positions of each member do not substantially change. Therefore, image formation or reading can be performed accurately.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of an image forming apparatus, FIG. 2 is a schematic configuration diagram of an exposure section, FIG. 3 is a graph representing a vibration spectrum, and FIG. 4 is a graph representing rigidity. Reference numerals in the figure: 10 Image forming apparatus 20 Rotating drum 28 to thermal development transfer section 34 Heating drum 36 Endless pressure belt 48 Bonding roller 49 - Peeling plate 50 - Separation roller 57/Guide 200 Belt 201... Guide bar 304... Pulley 311 Motor 313 - Measuring element 202 Side wall 310 Vibrator 312/accelerometer 314 - Preload spring 52 Separation belt 58 Conveying roller pair 16 Photothermographic material 22 Exposure head 32 - Image receiving material 1 n

Claims (1)

[Claims] In an image forming apparatus having vibration sources inside and outside of the image forming section or the reading section, the natural frequency of the image forming section or the reading section is determined from each frequency of internal vibration and external vibration spectrum in the image forming section or the reading section. An image forming device configured by adjusting the rigidity of the constituent members of the image forming section or the reading section so that