JPH03144627A - Image forming device - Google Patents

Abstract

PURPOSE:To appropriately cool an original platen by detecting the image information of a formed image and controlling the revolving speed or revolving time of a cooling fan based on the image information. CONSTITUTION:The image is exposed by irradiating an original with light from the light source of an exposing part M1, and the exposing part M1 is cooled by the cooling fan M2. An image information detecting means M3 detects the image information of the formed image such as reduction, variable density or the number of sheets from a switch and a sensor, etc. Based on the image information, the revolving speed or the revolving time of the cooling fan M2 is controlled by a cooling fan control means M4 to cool the exposing part M1. Thus, the temperature of the original platen, etc., is kept optimum in any usage state.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus equipped with a cooling fan.

[Prior Art] Conventionally, image forming apparatuses (for example, copying machines, etc.) are known to include an exposure section that irradiates a document with light and exposes an image using the reflected light.

Since the light source in the exposure area generates a lot of heat, the document table adjacent to the light source may become too hot. ) is attached adjacent to the exposure section.

Particularly in recent years, improvements in the performance of copying machines such as enlargement/reduction and color copying have required increases in exposure time and exposure intensity. time) is also increasing. Therefore, the rotation time of the cooling fan is usually set to be longer in accordance with cases where the longest exposure time is required, such as enlarged copying.

[Problems to be Solved by the Invention] However, in order to properly cool the document table etc. under any copying conditions, if the rotation time of the cooling fan is set in advance to be long, the use of the cooling fan becomes difficult. There was a problem that the time required was increased, resulting in a shortened service life, and the frequency of occurrence of failures was also increasing. On the other hand, if a sturdy ring fan that does not easily break down even when used for a long period of time is used, a problem arises in that the cost increases.

The present invention solves the above problems and provides an image forming apparatus that can maintain a document table, etc. at a suitable temperature under any usage conditions, and can maintain a long service life of a cooling fan used for cooling the document table. The purpose is to

[Means for Solving the Problems] In an image forming apparatus of the present invention (an image forming apparatus equipped with a cooling fan M2 that cools an exposure section M1 that exposes an image), an image that detects image information of the image to be formed is provided. The gist of the present invention is to include: an information detection means M3; and a cooling fan control means M4 that controls the rotation speed or rotation time of the cooling fan M2 based on the image information detected by the image information detection means M3.

[Function] In the image forming apparatus of the present invention, an image is exposed by irradiating a document with light from a light source in an exposure section M1, and the exposure section M is cooled by a cooling fan M2.

Here, the image information detection means M3 detects image information such as the scale, density, or number of images to be formed from a switch, a sensor, or the like. Based on the image information, the cooling fan control means M4 controls the rotation speed or rotation time of the cooling fan M2 to cool the exposure section M1. Thereby, overheating of the exposure section including the document table etc. can be efficiently prevented.

[Example] Hereinafter, in order to explain the present invention more specifically, an example will be given and explained.

FIG. 2 is a schematic cross-sectional view of a first embodiment of a photosensitive and pressure-sensitive copying machine (hereinafter referred to as a copying machine) which is capable of full-color copying. Note that the photosensitive paper (consisting of microcapsule paper and color developing paper) that enables such copying was developed in Japanese Patent Application Laid-Open No. 58-88.
This has been proposed in Publication No. 739, etc., and will not be described in detail here.

As shown in the figure, the copying machine 1 is composed of a document table unit 6 consisting of a document table glass 2 and a document table cover 4, the top plate of which is movable in the horizontal direction. The original can be placed face down. The document table unit 6 is driven and controlled in the left-right direction by a document table drive motor (not shown) via a pinion and a rack.

Further, a light source consisting of a halogen lamp 8 extending in a direction perpendicular to the direction of movement of the document table glass 2 and a semi-cylindrical reflecting mirror 10 arranged to surround it is fixed to the upper right side of the copying machine 1. , a line-shaped beam of light is irradiated toward the document table glass 2. Therefore, the light emitted from the halogen lamp 8 is
The entire surface of the document table glass 2 from the left end to the right end can be sequentially irradiated.

In order to use the light emitted from the halogen lamp 8 to irradiate the original with high efficiency, a beam flap 12 is arranged to the left of the light source to reflect the light that is not directed directly toward the original and use it again to irradiate the original. Furthermore, a photosensor 14 used for light amount feedback m control is arranged below the reflectors 8#, ]O.

To the right of the halogen lamp 8, there is a ventilation hole 16 for ventilation. There is.

On the operation panel 26 on the upper left side of the copying machine 1, there is a variable magnification switch 28 for specifying enlargement/reduction. A shading adjustment switch 30 for adjusting the shading of the original. A number setting switch 31 for setting the number of copies is provided.

The document table drive motor and the like are connected to an electronic control circuit (ECU) 40 shown in FIG. This E CtJ 4
0 Li, well-known CPU40a, ROM40b, RAM
40C, timer 40d, input interface 40e,
It is composed of an output interface 40f, a bus 40g connecting them, and the like. The output interface 40f is connected to the cooling fans 22 and 24 via the fan drive circuit 40h and to the pulse motor drive circuit 4.
0i to the document table drive motor, while the input interface e is connected to the photo sensor 14 degree variable magnification switch 28 . Darkness adjustment switch 30. It is connected to the sheet number setting switch 31 and the like. In addition, the ROM40
The number of revolutions of the cooling fans 22, 24, etc., which are set according to the copy conditions described later, are stored in b.

Next, the copying operations such as exposure and development of the copier will be briefly explained based on FIG. 2, along with other configurations.

The light reflected from the document placed on the plate document table glass 2 irradiated from the halogen lamp 8 passes through a filter 50 that changes the transmission characteristics of the light and enters the lens 52.The light is focused by the lens 52. The direction of the image is changed by two reflection mirrors 56 by 800 degrees, and an image is formed on the microcapsule paper 54 which is closely positioned below the exposure table 58.

On the other hand, the microcapsule paper 54 is wound around a cartridge shaft 60 and housed in a cartridge 62 disposed below the document platen glass 2. One end of the microcapsule paper 54 is wound through a number of rollers and a pressure developing device 64. It reaches the take-up shaft 66.

That is, the microcapsule paper 54 coming out from the lower part of the cartridge 62 is transferred to the feed roller 68 . After being guided by the tie roller 70 and passing below the exposure table 58, it is supplied to the pressure developing device 64. Thereafter, the microcapsule paper 54 that has passed through the pressure developing device 64 is guided to a peeling roller 72 and a meandering adjustment roller 74, and then wound onto a winding shaft 66. The unexposed microcapsule paper 54 after leaving the cartridge 62 is maintained in an unexposed state by a light-shielding cover 76.

The conveyance speed of the microcapsule paper 54 is controlled to be constant by the capsule paper feed roller 78 and matched to the movement speed of the platen platen glass 2, so that the microcapsule paper 54 has no original content when passing through the exposure platen 58. Latent images of predetermined lines are sequentially formed.

Further, a developer paper cassette 82 is provided below the pressure developing device 64 and stores the developer paper 80.
are taken out one by one by the half-moon roller 86 and then conveyed to the paper inlet of the pressure developing device 64. Therefore, the pressure developing device 641 includes the microcapsule paper 54 and the color developer paper 8.
0 are supplied in close contact with each other.

Then, in the pressure developing device 64, the microcapsule paper 5
The microcapsule surface on which the latent image No. 4 was formed and the developer paper 80
The roller 88 is sandwiched between the small-diameter roller 88 and the backup roller 90, and pressure is applied to the roller 88 and the back-up roller 90. This pressure destroys the unexposed microcapsules and forms an image on the color developing paper 80.

The microcapsule paper 54 and the color developer paper 80 that have come out of the pressure developing device 64 are conveyed by a capsule paper feed roller 78 and separated by a stripping roller 72, with the microcapsule paper 54 being separated upwardly and the color developer paper 80 being separated in the perpendicular direction. After the color developing paper 80 is accelerated in color development by the heat fixing device 92 and an image is formed,
The paper is delivered to the paper discharge tray 94 with the image side facing up. When the end of the document platen glass 2 finishes moving to a position facing the light source, copying of the document is completed and the halogen lamp 8 is turned off.

Next 1: The cooling fan 22 which is the main part of this embodiment
．． 24 will be explained based on the flowchart of FIG. This control changes the rotational speed of the cooling fans 22, 24 in accordance with the enlargement/reduction.

In addition, when this cooling fan 22.24e is rotated,
Air flows in from the gap under the original platen glass 2 along arrow A (FIG. 2), cools the original platen glass 2, and is discharged to the outside through the vicinity of the halogen lamp 8 and the ventilation hole 16.

First, based on the signal from the variable magnification switch 28, it is determined whether or not to copy at the same size.Step 100. (Hereinafter, steps will be referred to as S), if it is determined to be a full-size copy, the cooling fan 22.24 is rotated without changing the reference rotation speed or rotation time of the cooling fan 22.24. (S110) - Once this process ends.

On the other hand, if the copy is not the same size, the enlarged copy (for example, 2
(S120). If it is determined to be an enlarged copy, the rotational speed of the cooling fan 22, 24 is increased (for example, doubled) from the standard rotational speed for the same size copy without changing the rotation time.
Processing is performed (S130), and - the sample processing is ended.

On the other hand, if it is determined in step 5120 that the copy is not an enlarged copy, it is determined that the copy is a reduced copy (for example, 1/2 reduction), and the cooling fan 22. 24 is reduced (for example, 1/2 times) from the standard rotation speed for the same-size copy (S140), and the -sample processing is ended.

In other words, in the above processing, the exposure time differs depending on the copying conditions such as enlargement or reduction, and the temperature rise of the document table glass 2 etc. differs accordingly. The rotation speed is adjusted to cool the document table glass 2 and the like. For example, in the case of a 2x enlarged copy, the exposure time is usually required to be about 3 to 4 times that of a normal size copy.
[Adjustment of the above-mentioned rotation speed] 2) Control is performed to increase the cooling capacity.

By controlling the rotational speed of the cooling fans 22 and 24 in this way, the necessary amount of air can be blown only when necessary to cool the document table glass 2, etc., thereby extending the life of the cooling fans 22 and 24. can do. Also,
Since the rotation period is short, failures can be prevented from occurring. Furthermore, since there is no need to constantly set the cooling fans 22, 24 to rotate for a long period of time, such as when copying at the same size, the operating time is reduced, and a lower cost cooling fan 22, 24 can be used. Can be done.

Next, a second example will be described.

In this embodiment, the number of revolutions of the cooling fans 22 and 24 is adjusted based on a signal from the upper contrast adjustment switch 30.

That is, when setting the image to be brighter using the contrast adjustment switch 30, the amount of heat generated by the halogen lamp 8 increases because the time for irradiating the document with light becomes longer. Therefore, at this time, the cooling fan 22.2
Increase the number of revolutions in step 4 to increase the airflow, and
Increase the ability to cool etc.

On the other hand, in contrast to the above, when darkening an image (as the time for irradiating the original with light is short, the amount of heat generated by the Halo Def 9F 180 is reduced. Reduce the amount of air flow.

In this case, depending on the shading of the image, the cooling fan 22
．． By controlling the number of rotations of the cooling fans 22, 24, the life of the cooling fans 22, 24 can be extended, and failures can also be prevented.

Next, a third example will be described.

In this embodiment, the Kuonong Zuan 2
It adjusts the rotation speed of 2.24.

In other words, if the document is dark (black), it will absorb heat from the light source and become hot, so the document table glass 2 that is in contact with the document will
It also gets hot. Therefore, the light reflected from the original is detected by the photosensor 14 to detect the darkness of the original, and if it is determined that the original is dark, the number of rotations of the ring fans 22 and 24 is increased to increase the amount of air being blown. To improve the ability to cool the document table glass 2 and the like.

On the other hand, if the document is determined to be thin (white), the number of rotations of the cooling fans 22 and 24 is decreased to reduce the amount of air blown.

In this way, the cooling fan 22 detects the density of the original.
．． By controlling the number of rotations of the cooling fans 22 and 24, the life of the cooling fans 22 and 24 can be extended, and failures can also be prevented.

Next, a fourth example will be described.

In this embodiment, the rotational speed of the cooling fans 22 and 24 is adjusted based on a signal from the sheet number setting switch 31.

That is, when continuous copying is set by the number of copies setting switch 31, exposure is performed successively and continuously according to the number of copies to be made, so the amount of heat generated by the halogen lamp 8 increases. Therefore, at this time, the number of rotations of the cooling fans 22 and 24 is increased to increase the amount of air blown, thereby increasing the ability to cool the document table glass 2 and the like.

On the other hand, in contrast to the above, in the case of single copying, the next exposure is not performed from the start of copying until the paper is ejected, so the amount of heat generated by the halogen lamp 8 is reduced. Therefore, at this time, the number of rotations of the cooling fans 22 and 24 is reduced to reduce the amount of air blown.

In this way, depending on the number of copies, the cooling fan 22
．． By controlling the rotation speed of the cooling fans 22 and 24, the life of the cooling fans 22 and 24 can be extended in the same manner as described above.
It is also possible to prevent failures from occurring.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments in any way, and it goes without saying that it can be implemented in various forms without departing from the gist of the present invention.

For example, cooling fan 22.24 depending on copy conditions.
Instead of adjusting the rotation speed of the cooling fan, the rotation time of the cooling fan may be adjusted.

Further, in addition to the above, the control of the rotation speed and rotation time of the cooling fans 22, 24 may be changed in accordance with changes in various conditions of the exposure system.

[Effects of the Invention] As detailed above, the image forming apparatus of the present invention detects the image information of the image to be formed and controls the rotation speed or rotation time of the cooling fan based on the image information.
The document table etc. can be cooled appropriately by blowing air as needed. Furthermore, since the operating state of the cooling fan can be appropriately controlled, there is an advantage that the life of the cooling fan can be extended and failures can be prevented. Furthermore, since the operating time can be kept to a minimum depending on the copying conditions, a cooling fan with a simple structure and low cost can be used.

[Brief explanation of the drawing]

Fig. 1 is a basic configuration diagram illustrating the present invention, Fig. 2 is a schematic configuration diagram showing the overall configuration of the copying machine, Fig. 3 is a block diagram showing the electronic control device, and Fig. 4 is a diagram showing the drive control of the cooling fan. FIG. 1... Copying machine 2... Document glass 6... Document table unit 8... Halogen lamp 14... Photo sensor] 6... Ventilation holes 22, 24... Cooling fan 28... ·control panel

Claims (1)

[Scope of Claims] 1. In an image forming apparatus equipped with a cooling fan that cools an exposure section that exposes an image, an image information detection means for detecting image information of the image to be formed; and an image information detection means for detecting image information. An image forming apparatus comprising: cooling fan control means for controlling the rotation speed or rotation time of the cooling fan based on the image information obtained.