JPS6037581A - Copying machine - Google Patents

Abstract

PURPOSE:To improve heating efficiency and copying performance by providing a photoselectively absorbing film on the inside surface in the hollow part of a heating roll. CONSTITUTION:A heating roll 12 for fixing toner is made hollow and a light source 13 consisting of visible or near IR rays is provided in the hollow layer so that the roll 12 heated by the same. A photoselectively absorbing film is formed on the inside surface in the hollow part of the roll 12. The photoselective absorptivity of said absorbing film is required to have >=50%, more preferably >=80% average absorptivity of visible and (or) near IR rays. A better result is obtd. if the average emissivity of the film within 150-250 deg.C is <=40%, more preferably <=10% when the film is heated to said temp.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a copying machine having a heating roll with a built-in light source for constant toner wear. More specifically, in electrophotographic copying, electrostatic copying, and other types of copying machines that use toner (heat-melting powder ink) to fix the phenomenon, the heating roll that heats the toner is heated more quickly and the heating efficiency is increased. The present invention relates to a copying machine that improves copying performance and eliminates various fΦ troubles.

In recent years, copying, mainly electrophotographic copying and electrostatic copying, has become extremely versatile due to the development of copying system technology. Moreover, the so-called "start-up time" required for a machine to become ready for copying after the power is turned on has also been significantly shortened (3). The biggest factor that determines this rise time is 1. In this copying method, on the copy surface such as copy paper,
In any case, a heated roll that heats and melts the developed toner is used to heat and fuse the developed toner. The temperature rises at a certain rate.

By the way, the current heating method of the above-mentioned copying machine using a heating roll for constant toner wear is such that the inside of the roll is hollow;
A straight bulb of a tungsten lamp or a tungsten norogen lamp is inserted into this hollow interior, and the roll is heated from the inner surface of the roll mainly by radiation and convection heat transfer using the light beam energy from the lamp. The toner heat fixing roll is mainly composed of various metal rolls, and the inner surface of each roll is made of the metal itself of the various rolls,
I don't see any special thermal considerations, and I don't see any suggestions for specific ideas to improve them. In the relevant industry, the above
) Although various efforts have been made to shorten the heating time, the reality is that the only way to shorten the heating time is to increase the power of the lamp. be.

Incidentally, although the heating time has certainly been shortened to some extent by increasing the power of the lamp, excessively increasing the power of the lamp is accompanied by the following drawbacks.

III] First, at the start of the switch-on input,
Due to the input of excessive power, the lamp temporarily has an excessive output and is overheated, which increases the overload of the lamp and shortens its life.

Secondly, 1. The surface temperature of the constant wear heating roll becomes too high than the original optimum fixing temperature of the toner;
At the same time, the surface to be copied (such as paper or a filter used for overhead projects, etc.) is also deviated above the heat-resistant temperature of the -L limit or the optimum temperature, and as a result, the toner is heated to a certain temperature. They may remain unnecessarily on the surface or stick to the surface, causing problems with the scraping and cleaning/stem, or may cause deformation, wrinkles, etc. on the surface to be copied, such as paper, etc. This can cause what is called a "paper jam."

Thirdly, the separation claw that separates the copying material from the toner constant-wear heating roll may deteriorate or expand abnormally due to the excessive temperature rise, resulting in "paper jams" and the like. It is also the cause of problems. In addition, the use of extra electrical energy increases energy consumption and requires additional protection systems to prevent excessive current flow.

In view of these circumstances, the inventors of the present invention, as a result of intensive study,
It has now been possible to achieve the revolutionary effect of the present invention in the heating system of the copying machine.

That is, in a copying machine in which thermal energy from a light source is applied from within the hollow part of a heating roll for constant toner application, a light selective absorption film is formed on the surface inside the hollow part of the heating roll for constant toner application. The main topic is copying machines that

Hereinafter, the configuration of the present invention will be explained in detail.

The figure is a schematic explanatory diagram showing the main parts of a copying machine according to an embodiment of the present invention, in which an exposure section 2 is provided along the periphery of a photosensitive drum 1 at the top, and a toner cartridge 6 is provided at the side. and a toner applying section 5 consisting of a brush 7,
Further, on the opposite side, there are provided a supply section 8 for a copying material 11 such as paper, and a fixing section 9 for fixing the copying material after toner transfer.

An exposure section 2 uses light from a light source 3 to transfer an image of a copying object 14 (original document, etc.) onto an exposure glass 1° to a photosensitive drum 1 through a lens 4.
The top is exposed to light. The photosensitive drum 1 rotates and attaches toner to the surface exposed to light in the toner applying section 5,
It further rotates to transfer the toner on the photosensitive drum 1 onto the object 11 to be copied. The copying object 11 to which the toner has been transferred is heated in the fixing section 9 to melt and fix the toner.

The fixing unit 9 includes a heating roll 12 having a hollow portion and a light source 13 disposed therein, and is heated by radiant heat from the light source 16.

First, in the present invention, the copying machine adopts a method in which the toner finally developed on the surface to be copied (paper, etc.) is heated to melt and fix it. Mainly, the toner and the surface to be copied come into contact with the fixed fixing roll and are heated.

Copying machines using these toners use so-called photoconductors (
electrophotographic copying machines that use organic photoconductors such as selenium, cadmium sulfide, and polyvinylcarbazole) as copy masters; or that use simple dielectrics as copy masters, or that the copying material itself is dielectric and does not perform so-called toner transfer. It is something. In any case, the main focus is on so-called electrostatic copying machines that develop and fix toner by creating an electrostatic latent image by applying static electricity and removing static electricity according to the original pattern, but it should not necessarily be limited to these. This is self-evident, and in any case, any copying machine that uses a constant amount of toner will suffice.

Next, the toner fixing heating roll is hollow inside, and a light source mainly consisting of visible light and/or near infrared rays is used in the hollow layer as a heating source to heat the roll. Adopt a method. Generally, various heating methods can be considered, but although direct electric heating is efficient and looks good, it is mechanically difficult due to the formation of the current collecting electrode and its safety measures for the user. However, a light source having a high light source temperature and an efficient light source of the above wavelength is preferable, and generally the most preferable one is a tungsten lamp, and the more preferable one from the viewpoint of lamp life is a halogen lamp. Although these mainly span a wavelength of 400 to 3,000 nm, it is obvious that the wavelength is not necessarily limited to this. By the way, Rumph.

Due to the nature of That's true.

A so-called lamp consisting of the above-mentioned light source is inserted and attached to the internal hollow layer of the toner constant fixing heating roll, but these are often straight bulbs due to the shape of the copying machine.
If necessary, it can be a lamp light source of an appropriate shape. A light selective absorption film, which is the most important feature of the present invention, is formed on the hollow inner surface of this fixing heating roll.

The light-selective absorption properties of this light-selective absorption film are limited to visible light and/or light.
Or the average absorption rate of near-infrared rays (this is α) is 50%
It is necessary that it is above.

Preferably, α is 80 or more.

Next, when this film is heated between 150°C and 250°C, the average emissivity at that temperature (which is referred to as ε) must be 40 cm or less, and furthermore, ε must be at most 20 cm.
H, particularly preferably 1 to ε is 10% or less. In other words, the η ratio is preferably 1.25 or more, generally 3 or more.

The following methods were adopted as specific examples of the methods for measuring α and ε in the present invention.
Of course, the present invention is not limited to this method.

(1) α: Hitachi self-recording spectrophotometer 323 manufactured by Hitachi, Ltd.
In the mold, calculate the integrated average value (γ) of the total light reflectance between wavelengths 300 to 2,400 nm, and from this, the formula, α=10
Value calculated from 0-γ.

(2) ε: Infrared spectrophotometer IRA manufactured by JASCO ■, -
Values measured using Type 2 at a wavelength of 25 to 25μ, with ε of a standard sample of a perfect black body set to 100.

There are various methods to exert these light absorption selectivity [7], and basically any method can be used.
In particular, Co, Ni, Cu, Cr.

Mn, Sn, Mo, Cd, Fe, Pb, Z
n, A/, Ba, Sr.

K oxides and sulfides are preferable as the central substance that basically produces the selective absorption property. These substances may be used alone, or may be a composite or mixture of amounts of these substances. Furthermore, it may be mixed, composited, or laminated with other elements, molecules, and even various polymers, especially so-called binders such as heat-resistant polymers. Especially these oxides.

Among sulfides, oxides of nickel (such as so-called black nickel), copper, cobalt, chromium, and tin are particularly good. In addition, metal salt electrolysis products include Co, Ni, Cu, Cr, and Mn after anodizing in an aqueous solution of sulfuric acid, oxalic acid, phosphoric acid, etc.
, Sn, Mo, Cd, Fe, Pb.

Zn, A13. An electrolytic product obtained by electrolytically oxidizing it with an aqueous solution containing at least one metal salt of Ba, Sr, or K and forming it on the inner surface of the roll of the base material is preferable, but it is not necessarily limited thereto. . In addition, alkaline etching.

Degreasing by acid etching, surfactant treatment, etc.

After several layers of chemical treatment, Co, Ni, Cu, C
r, Mn.

A surface film provided by treatment in an aqueous solution containing at least one metal salt of Sn, Mo, Cd, Fe, or Pb is also preferred. However, this electrolytic oxidation method can generally be used to form a film from several tens of OA to several hundreds of micrometers, and various morphological/shape factors (11) can also be devised. As another film forming method, a vacuum deposition method in a broad sense is employed. After mere thermal evaporation, oxidation treatment or sulfurization treatment may be performed, but sputtering is also possible. It is also possible to deposit the compound and deposit it at the same time by ion blasting or reactive sputtering. It is also very useful to mix particles of these substances with various other binders, spray coat them, and then bake them. In particular, after immersing the particles inside the roll, drain off the excess coating liquid and bake them at a high temperature. It is preferable to improve heat resistance and deterioration resistance. In such cases, when a polymer is used as a binder, polyimides and certain heat-resistant silicone fluororesins are also useful. In these cases, mutual lamination or composites of the various films mentioned above are useful, but
Since there are too many possible combinations, the explanation will be too redundant, so we omit it. Note that the fusing temperature of toner can be varied depending on the type of toner, but generally it is currently 150 to 250°C, so it is intentionally set at 150 to 250°C.
Although the emissivity is expressed as the emissivity at a temperature of 0 (12) °C, even if the fixing temperature is higher or lower than this, these light selective absorption properties can be inspected by simulating the temperature range. It is something.

Next, the material of the main body of the fixing heating roll can be freely selected from various materials, such as metals, plastics, and ceramics, but it has been found that aluminum or an aluminum alloy is particularly suitable in the present invention. this is,
When a light distribution selective absorption film is formed on an aluminum base material, heat radiation and heat dissipation at, for example, 150 to 250°C can be further prevented. Note that aluminum also has the secondary advantages of being lightweight and relatively inexpensive and economical, but it is obvious that this is due to the fact that the above performance factors are the main factors. . In particular, it is useful, and even essential, when forming an oxide film subjected to anodizing treatment.

The effects of a copying machine formed with such materials, structures, and configurations will be explained in detail below through Examples and Comparative Examples. Surprisingly, the heating time was shortened from about μ in the conventional method to a false time.
The so-called start-up access time of a copying machine has been shortened from the conventional 3 minutes to 1 minute to 1 minute to 20 seconds, and even less than 20 seconds, contributing to improved copying efficiency and, in particular, to the comfort and smoothness of copying work. , which has great effects.

Example I Using an aluminum pipe with an inner diameter of 34 mm, an outer diameter of 42 mm, and a length of 330 mm having a purity of JIS Al2S3, the inner surface of the pipe was coated with several layers of fine sand blasting, degreased, and then treated with 10 weight phosphoric acid as the first step. % in an electrolytic solution at a temperature of 27° C., the aluminum pipe was used as one pole and the carbon was used as the other pole, and a DC voltage of 1.5 V was applied to perform anodization treatment for 15 minutes. Next, as a second step, this was subjected to a coloring electrolytic treatment for 20 minutes in an aqueous solution at 27°C containing 5 parts by weight of cobalt sulfate and 2 parts by weight of boric acid using the same electrode configuration as in the first step and applying a DC voltage of 15 V. After that, the third step is to cut the outer surface of the pipe to an outer diameter of 40 mm.
An aluminum pipe for fixing rolls with a light-selective absorption film on the inner surface was manufactured. Next, the fourth step (~te, inner diameter 14 dragons,
It is a pipe made of the same material with an outer diameter of 20mm and a length of 30mm, and a lamp insertion hole having a collar with a diameter of 40mm at one end is welded to both ends of the rolled aluminum pipe and the collar.
As a fifth step, a fixing roll for a toner image transfer type dry electrostatic copying machine was manufactured by coating the outer surface of the roll portion with a polytetrafluoroethylene resin by a conventional method.

In addition, in order to measure the light selective absorption of the inner surface of the aluminum pipe at the end of the third step, the same material and thickness as the aluminum pipe were used.

After processing a flat plate with the same surface area under the same conditions as the aluminum pipe up to the second step, the average absorption rate (α) of visible light and near-infrared rays at room temperature and the average absorption rate (α) at 200°C of the obtained flat plate with a light-selective absorption film were evaluated. When the average emissivity (ε) was measured, it was (15) α292'% and ε: 10%, respectively.

The inside of the fixing roll has a diameter of 10 mrn and a length of about 400 m.
The fixing roll equipped with a 11L halogen lamp was used in a copying machine having a normal toner image transfer type dry electrostatic copying mechanism (
ppc) was incorporated into the fixing device. That is, PPC consists of a charging function consisting of a selenium drum having a photosensitive function, an exposure function to create an electrostatic latent image, a developing function using a powder developing roll, a transfer function to copy paper, and a fixing function to fix the toner image on the paper. , paper feed, pressure roll (lower roll), and the above fixing roll (10 rolls)
, peeling claw section, and upper and lower cleaning sections (cleaning roller for the lower roll.

The time required for the roll surface temperature to reach 200°C after the halogen lamp was turned on for the fixing roller of this PPC device, which was composed of a clean web mechanism (for the upper roll), was measured and found to be 45 seconds on average. However, after manually applying power to this PPC, the ``startup time'' at which copying was actually possible was shortened to 53 seconds (16).

Comparative Example 1 Regarding the fixing roll manufactured under the same conditions as in Example 1 except that it did not have a light-selective absorption film, the time required for the roll surface temperature to reach 200°C after the rogen lamp was turned on was measured, and the average temperature was 105°C. It was seconds. in this case,
The shortest rise time for P mice was 128 seconds.

Example 2 Made of aluminum alloy containing 0.12% copper, 0.08% silicon, 0.7% iron, 0.01% manganese, and 0.01% magnesium, inner diameter 4 mm, outer diameter 42 mm, length 330 mm. Using my friend's aluminum pipe, the inner surface of the pipe was degreased by a conventional method and pickled in a chromic acid/sulfuric acid solution, and then treated under the conditions shown in Table 1 as the first and second steps. From the third step onward, p-section fixing rolls having various light selective absorption films were manufactured in the same manner as in Example 1.

The results of measuring α and ε of these light-selective absorption films in the same manner as in Example 1 and the results of the fixing roller having these light-selective absorption films on its inner surface at temperatures ranging from room temperature to 200°C.
The temperature time and 1) rise time as pC are also shown in Table-1.

Comparative Example 2 In Example 2, the fixing roll manufactured under the same conditions except that it did not have a light-selective absorption film was measured in the same manner as Comparative Example 1, and the heating time from room temperature to 200°C was measured, and the average was 109 seconds, and the minimum rise time as ppc was 131 seconds.

(Margins below this page) (19) Example 3 Tricobalt tetroxide powder was prepared by calcining highly pure cobalt monoxide in air at 700°C for 1 hour. 100 parts by weight of tricobalt tetraoxide heat-resistant cone (“Toray Silicone” 805 resin (xylene solution,
Solid content: 50 parts by weight, 15 parts by weight, cellosolve acetate
1-1, 15 parts by weight made of SUS, 5. , at a rotation speed of 100 rpm using an M-sized ball mill (balls: SUS 304, 25φ, filled with approximately 100 lbs.).

A paint for a photoselective absorption film was prepared by pulverizing and stirring for 24 hours.

The above paint was spray-coated uniformly and thinly on the inner surface of an aluminum pipe of the same quality and size as in Example 1 (inner surface sandblasted and degreased) and treated with hot air at 150°C for 30 minutes, resulting in an average coating weight of 5 g/Tn2. An aluminum pipe for a PPC fixing o-le with a light-selective absorption film was created. Thereafter, a fixing roll and a ppc equipped with the fixing roll were manufactured in the same manner as in the fourth step and subsequent steps of Example 1.

The temperature rise time from room temperature to 200°C on the surface of the fixing roll is 50 seconds + the shortest rise time as ppc is 5
It was 7 seconds.

Example 4 An aluminum pipe of the same quality and size as in Example 2 was pretreated by cleaning with an aqueous caustic soda solution and neutralizing with an aqueous nitric acid solution, and then treated with 2 parts by weight of manganese sulfate, 2 parts by weight of nickel sulfate, and 1.2 parts by weight of sulfuric acid. 20 in aqueous solution at 65°C.
Processed for minutes. Then add 1.5 parts by weight of ammonium molybdate tetrahydrate and 0.5 parts by weight (cobal sulfate) at 65°C.
Blackening was achieved by treatment in an aqueous solution for 15 minutes.

Hereinafter, by applying the same steps as the third step and subsequent steps of Example 1, p
A fixing roll for PC and a PPC equipped with the fixing roll were manufactured.

The temperature rising time from room temperature to 200° C. on the surface of the fixing roll was 58 seconds. Moreover, the shortest rise time as ppc was 65 seconds.

[Brief explanation of drawings]

The figure is a schematic explanatory diagram showing the main parts of a copying machine. (21) 1... Photosensitive drum, 2... Exposure section, 3... Light source,
4... Lens, 5... Toner application section, 6... Toner cartridge, 7... Brush, 8... Supply section, 9
... Fixing section, 10... Exposure glass, 11... Subject to be copied, 12... Heating roll, 13... Light source. Agent: Patent Attorney Shin Ogawa - Patent Attorney Ken Noguchi Patent Attorney Kazuhiko Saishita (22)

Claims (1)

[Scope of Claims] 1. In a copying machine in which a heating roll with constant toner wear is heated by a light source provided in a hollow part within the roll, a light selective absorption film is provided on the inner surface of the hollow part of the heating roll. A copying machine characterized by: 2. The light selective absorption film has an average absorption rate of visible light and/or near infrared rays of 50 coefficients or more, and an average emissivity of 40% or less in the range of 150 to 250°C, according to claim 1 copy machine. 3. The base material of the heating roll for constant toner wear is made of aluminum or aluminum alloy, and the inner surface of the hollow part of the heating roll contains at least one of sulfuric acid, phosphoric acid, and phosphoric acid in the first step. An oxide film is first formed by anodizing in an aqueous solution, and then, as a second step, Co, Co,
Ni, Cu, Cr, Mn, Sn, Mo, Cd, Fe,
Pb. 2. The copying machine according to claim 1, wherein the photo-selective absorption film is provided by electrolytic treatment with an aqueous solution containing at least one metal salt of Zn, AJ, Ba, Sr, or K. 4. If the heated roll with constant toner wear is made of aluminum or aluminum alloy, the inner surface of the hollow part of the heated roll is first degreased and/or After several layers of chemical treatment, Co, Ni, Cur C
r, Mn, Sn, Mo. 2. The copying machine according to claim 1, wherein a light-selective absorption film is applied to the inner surface of the hollow portion by treatment in an aqueous solution containing at least one metal salt of Cd, Fe, or Pb. 5 The light selective absorption film is made of Co, Ni, Cu, Cr.
, Mn. Sn, Mo, Ccl, Fc, Ph, Zn,
Claim 1 consisting of a film whose main component is at least one of oxides and sulfides of Alg, Ha, Sr, and K.
Copying machine mentioned in section. 61. The copying machine according to claim 1 or 5, wherein the heating roll body for constant oil is made of aluminum or an aluminum alloy. 7. The copying machine according to claim 1, 2, 3, 4, 5, or 6, wherein the heating light source is a tungsten lamp or a halogen lamp.