JP3853141B2 - Flash fixing device and image recording device using the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement of an image recording apparatus, and more particularly to an improvement of a flash fixing apparatus used in an electrophotographic image recording apparatus.
[0002]
[Prior art]
Conventionally, as an electrophotographic fixing method, there is a thermal roller fixing method in which a toner on a recording medium (hereinafter abbreviated as paper) is fixed by a thermal roller, or an instantaneous flash of a flash lamp. A flash fixing method is used in which the toner on the paper is fixed using thermal energy.
[0003]
Among them, the flash fixing method can be fixed in a short time without contact with the paper as compared with the thermal roller fixing method, and thus is frequently used in an electrophotographic method apparatus that conveys the paper at a high speed.
[0004]
However, since the flash fixing method is fixed in a short time and needs to be performed at a higher temperature than the thermal roller fixing method, smoke and gas are easily generated due to melting of the toner during high temperature fixing. Also, some toner on the paper before fixing is scattered.
[0005]
The smoke, gas, and scattered toner (hereinafter collectively referred to as pollutants) adhere to the flash lamp and reflector, reducing the amount of flash lamp light and the reflectivity of the reflector, reducing the thermal energy on the paper surface, and fixing. Reduce the fixing ability by lowering the temperature.
[0006]
Therefore, in order to protect the flash lamp and the reflection plate from contaminants, a flash fixing device in which a transparent shielding member is provided between the paper and the flash lamp is employed.
[0007]
However, even in this configuration, instead of pollutants contaminating the shielding member, the transmittance of the shielding member is lowered, leading to a decrease in the heat energy on the paper surface, lowering the fixing temperature and lowering the fixing ability. Preventive measures such as cleaning the member are necessary.
Further, there is a problem that the temperature of the flash lamp and the shielding member is increased during continuous operation, and the paper is burnt by touching the high-temperature shielding member when a paper jam occurs.
[0008]
For this reason, for example, in Japanese Laid-Open Patent Publication No. 57-23985, as a means for solving the problems of the cleaning and the temperature rise, as shown in FIG. 4, air is applied to the back surface of the glass transparent shielding member 42 serving as a fixing device window. A method has been proposed in which a flow is created, the scattered toner and gas are recovered, the glass 42 is cooled, and the recording paper 47 is separated from the glass 42.
[0009]
[Problems to be solved by the invention]
However, in the conventional configuration as described above, the flow rate balance in the air flow path between the blowing duct 50 side and the suction duct 51 side that creates the air flow is not necessarily uniform over the entire area of the recording paper. The scattering toner and the gas recovery between the paper 47 and the glass 42 are non-uniform, and the fixing of the glass 42 due to the variation in the transmittance of the glass 42 due to the contamination of the glass 42 from the low flow rate portion with the passage of time. Variation in cooling occurs. Further, in the problem that the recording paper 47 touches the glass 42 and burns, air is blown out toward the recording paper 47 on the blowing duct 50 side, and there is an effect of separating the recording paper 47 from the glass 42, but on the suction duct 51 side. In this case, the effect of separating the recording paper 47 from the glass 42 is insufficient.
The present invention solves such a conventional problem, uniformly eliminates contaminants by uniformly supplying air to the paper surface side of the shielding member, improves the uniform cooling capacity of the shielding member, and paper on the back surface of the shielding member. An object of the present invention is to provide a flash fixing device having a contact prevention function.
[0010]
[Means for Solving the Problems]
The present invention, as an embodiment, a flash lamp housed in the reflector,
A transparent shielding member provided on the surface of the reflecting plate facing the recording medium and having a through hole in the thickness direction, and air provided on the paper supply side of the reflecting plate with respect to the paper transport direction There is provided a flash fixing device comprising air blowing means which forms air flow along the surface of a shielding member.
The shielding member may be made of a high heat resistant resin, and the through holes may be arranged in a staggered manner.
Further, the through-hole provided in the shielding member extends from the surface on the flash lamp side of the shielding member to the back surface on the recording medium side from the center in the width direction of the recording medium in the lateral direction of the recording medium width. Then, it may be opened obliquely toward the recording medium traveling direction.
As an embodiment of the present invention, the flash fixing device described above may be provided, and a means for exhausting gas along the rear surface of the shielding member on the recording medium side may be provided.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to FIGS.
[0012]
FIG. 1 is a block diagram of an image recording apparatus to which the present invention is applied. When image data for one page of paper is accumulated in the image data receiving apparatus 2, a recording cycle is started. In recording, the photosensitive drum 3 is rotated clockwise, the surface thereof is uniformly charged by the pre-charging device 4, and then image data is applied to the surface of the photosensitive drum 3 by a laser (not shown) in the exposure device 5. An electrostatic latent image is formed by performing exposure based on the image. This electrostatic latent image is developed by the developing device 6 and becomes a toner image on the surface of the photosensitive drum 3.
[0013]
On the other hand, the sheet 7 is fed out from the sheet supply device 8 and is conveyed to the transfer charging device 10 in synchronism with the toner image on the surface of the photosensitive drum 3 by the sheet conveying mechanisms 9a and 9b. The toner image is transferred to the sheet 7. Thereafter, the sheet 7 is conveyed to the flash fixing device 20, and the transferred toner image on the sheet 7 is melted and fixed on the sheet 7 by the thermal energy generated by the instantaneous flash of the flash lamp 21. The sheet 7 that has been fixed is stored in the sheet storage device 11.
[0014]
Further, the surface of the photosensitive drum 3 that has been transferred is cleaned by the cleaner device 12. Thus, the operation for one cycle of the image data for one page is completed.
[0015]
Embodiments of a flash fixing apparatus and an image recording apparatus according to the present invention will be described below.
[0016]
FIG. 2 is a side view of the flash fixing device 20 and the air blowing means 30 and the exhaust means 31 of the present invention, and FIG. 3 shows an example of drilling the through hole 23 of the transparent shielding member 22 of the present invention.
[0017]
In the flash fixing device 20 of FIG. 2, the flash lamp 21 repeatedly heats a flash several times while the paper 7 is passing at a timing when the paper 7 passes under the flash fixing device 20 by a driving power source (not shown). At this time, the toner image on the paper is exposed to a high temperature and the toner is melted and fixed on the paper 7. In order to protect the flash lamp 21 and the reflecting plate 24 from contaminants generated during fixing, a shielding member 22 having a large number of through holes 23 is provided.
[0018]
FIG. 3 is a perspective view specifically showing an example configuration of the shielding member 22, and the through holes 23 are arranged in a staggered manner with a substantially uniform distribution over the entire area, and the shielding member 22 is bordered on the center in the paper width A direction. The front and rear surfaces of the shield member 22 have diagonal through-hole groups 23a and 23b that are formed in the left and right outer directions of the sheet width and obliquely toward the conveyance direction A of the sheet 7, respectively. Further, in the center in the paper width A direction and the left and right outermost sides of the above-described oblique through hole groups 23a and 23b in the left-right outer direction, the paper transport direction from the surface of the shielding member 22 toward the rear surface of the shielding member 22 Through-hole groups 23a ′, 23b ′, and 23c ′ that are opened obliquely in parallel with A are provided.
In order to form such a large number of through-holes, it is preferable from the viewpoint of molding work to use a heat-resistant resin, for example, a polyimide resin, instead of the conventional glass plate as the material of the shielding member.
[0019]
Referring again to FIG. 2, toward the through hole 23, the shielding member 22 from the air blowing means 30 provided on the surface of the shielding member 22 on the paper supply side (hereinafter referred to as upstream) with respect to the paper conveyance direction A. The air blown out along the surface forms an air flow A along the surface of the shielding member 22.
[0020]
The airflow A flowing along the surface of the shielding member 22 is blown out as an airflow B at the through hole 23 toward the paper storage side (hereinafter referred to as downstream) on the back surface side of the shielding member 22 through the through hole 23.
[0021]
The blown airflow B acts in a direction to separate the paper 7 from the back surface of the shielding member 22 and also causes contaminants generated during fixing to drift between the paper 7 and the back surface of the shielding member 22 to the downstream side. The air is exhausted by an air exhaust means 31 provided at the downstream end, and is discharged outside an image recording apparatus (not shown).
[0022]
Further, by opening the through hole 23 as shown in FIG. 3 described above, the airflow B blown from the oblique through hole groups 23a and 23b spreads the paper in the paper left and right direction from the center of the paper in the paper traveling direction. Since the airflow B blown out from the outermost through hole groups 23a 'and 23b' blows out in the paper traveling direction, the paper B is generated outwardly from the oblique through hole groups 23a and 23b. It acts to correct the flow of air to be blown and diffused in the direction of paper travel, preventing the diffusion of contaminants and improving the recovery efficiency.
[0023]
Further, the shielding member 22 is cooled by this series of air flows.
In addition, the through-hole 23 opened to the shielding member 22 may be the arrangement shown in FIGS. 5 and 6 in addition to the above-described FIG. 3, or may be in any other arrangement or direction.
[0024]
It is also conceivable that the flow of air blown to the shielding member 22 is directed from the downstream side toward the upstream side. In this case, the hot air that has cooled the shielding member 22 is transferred to the printing process side of the image recording apparatus of the present application such as the photosensitive drum 3. The adverse effect on print quality due to high temperatures is unavoidable.
[0025]
At this time, even if the air blown out along the surface of the shielding member 22 is provided with a wind direction guide 25 at the outlet of FIG. 2, the air flow is divided into two as the air flow C toward the flash lamp 21, and the flash lamp 21 is cooled. good.
[0026]
【The invention's effect】
As described above, according to the present invention, a plurality of through holes are provided in the shielding member, and an air flow is created from the upstream side of the shielding member surface to the downstream side of the shielding member back surface through the through hole. effective.
[0027]
1. Uniform air is blown out to the paper side through a through-hole formed in the entire surface of the shielding member for every narrow area, preventing contamination from adhering to the back surface of the shielding member, preventing a decrease in transmittance on the shielding member, and fixing ability Can be prevented.
[0028]
2. Since air blows over the entire surface of the shielding member toward the sheet through the through hole, scorching due to contact between the sheet and the shielding member is prevented.
[0029]
3. Since air flows through the front and back surfaces of the shielding member and the inside of the through-hole, the cooling area increases, the cooling efficiency improves, and the temperature rise of the shielding member is suppressed. Can be reduced.
[0030]
4). The air blown to the shielding member is divided into two by the air guide and blown to the flash lamp. Conventionally, a cooling member dedicated to the flash lamp has been required, but the dedicated member becomes unnecessary and the cost can be reduced by reducing the number of parts. It becomes.
[0031]
That is, the present invention not only improves the fixing ability and prevents paper scorching in the flash fixing device, but also gives good results in reducing the cost of the image recording device.
[Brief description of the drawings]
FIG. 1 is a block diagram of an image recording apparatus. FIG. 2 is a flash fixing device and air supply / exhaust means.
[Fig. 4] Conventional example of flash fixing device [Fig.
FIG. 6: Drilling example 3 of shielding member through hole
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Image recording device 2 Image data receiving device 3 Photosensitive drum 4 Pre-charging device 5 Exposure device 6 Developing device 7 Paper 8 Paper supply device 9a Conveying mechanism 9b Conveying mechanism 10 Transfer charging device 11 Paper storage device 12 Cleaner device 20 Flash fixing device 21 Flash lamp 22 Shield member 23 Through-hole 23a Oblique through-hole group 23b Oblique through-hole group 23a 'Through-hole group 23b' Through-hole group 23c 'Through-hole group 24 Reflector 25 Wind direction guide 30 Outlet means 31 Exhaust means

Claims (4)

A flash lamp (21) housed inside the reflector (24);
A transparent shielding member (22) provided on a surface of the reflecting plate (24) facing the recording medium (7), the shielding member (22) having a through hole (23) in the thickness direction, and paper conveyance Air blowing means (30) provided on the paper supply side of the reflector (24) with respect to the direction (A), the air blowing means (A) forming an air flow (A) along the surface of the shielding member (22). 30) . A flash fixing apparatus comprising: The flash fixing device according to claim 1, wherein the shielding member (22) is made of a high heat-resistant resin, and the through holes (23) are arranged in a staggered manner. The through hole (23) provided in the shielding member (22) is formed on the recording medium (7) from the surface on the flash lamp (21) side of the shielding member (22) with the center in the width direction as the boundary. a said recording medium (7) wide lateral outward direction on the back surface of the medium (7) side, the recording medium (7) according to claim 1 or 2, wherein the bored obliquely toward the traveling direction Flash fixing device. Comprising a flash fixing device according to any one of claims 1, 2, 3, and shielding member (22) of said recording medium (7) side is provided with means (31) for exhausting the gas along the back surface An image recording apparatus.

Images