JPH1165405A - Original feeding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cool an original placing plate and to efficiently prevent the temperature rise of the plate by making at least one among plural carrier rollers a heat pipe. SOLUTION: A pair of carrier rollers 24 and 25 of an original feeding device is provided with a heat pipe construction. The rollers 24 and 25 are rotatably supported at bearings 34 and 35 of supporting plates 60 and 61 using a right roller shaft 31 and a left roller shaft 33. A pair of the rollers 24 and 25 is made of, for example, hollow iron pipes having superior heat conductivity and adopts a so-called heat pipe type in which pure water is sealed as a cooling medium. Since the heat generated in the device is quickly radiated from cooling fins 32 by the rollers 24 and 25 of the heat pipe mechanism a carrier belt is cooled and the original placing plate which is brought into contact with the belt, is also cooled. Thus, at the time of using the device in a so-called platen mode, a user does not feel hot and can perform the operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document feeder, and more particularly, to a document feeder for feeding a document to a document placing plate (contact glass) of a copying machine or the like.

[0002]

2. Description of the Related Art A copying machine provided with a document supply device for supplying a document to a document placing plate (contact glass) can automatically and continuously supply a document from a document table onto the document placing plate. (ADF method). This type of document supply device has a plurality of transport rollers, and the plurality of transport rollers include a transport roller on a document reference side and a transport roller on a document leading end for driving a transport belt. The belt is hung on the rollers, and the movement of the belt feeds the originals one by one from the original platen onto the original placing plate, and irradiates the original on the original placing plate with light from the exposure lamp of the optical device. To read the contents of the original.

[0003] When a higher copy speed is required, the frequency of scanning by the optical device increases, and the original placing plate is heated at a higher temperature by the light source of the optical device. Therefore, a blower fan is used for the purpose of increasing the cooling capacity in order to prevent the heating of the document placing plate. JP 5
The document scanning apparatus disclosed in Japanese Patent Application Publication No. 197038 has a document placing plate, an optical system for scanning the document, a document size detection sensor, a rod below the document placing plate, and a document placing device. A fan for sending cooling air into the space below the mounting plate, and a cooling air deflection guide provided on the rod body are provided.

[0004]

However, in order to increase the cooling capacity of the blower fan, it is conceivable to increase the air flow of the blower fan. The device becomes large.

In the document supply apparatus disclosed in Japanese Patent Application Laid-Open No. Hei 6-166448, the optical system is fixed, documents can be automatically supplied one by one from a document bundle, and grooves are formed on the surface of the document pressing roller. It is disclosed that a ventilation duct for sending air is provided between the document holding roller and the document placing plate. However, with such a structure, it is difficult to efficiently supply the air between the document pressing roller and the document to cool the document placing plate efficiently.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to provide a document feeder that can cool a document placing plate and efficiently prevent the temperature of the document placing plate from rising.

[0007]

According to a first aspect of the present invention, a belt is moved by a plurality of transport rollers,
In the document feeder, which feeds documents one by one from the platen onto the document placing plate and irradiates the document on the document placing plate with light from the light source of the optical device to read the contents of the document, At least one of the rollers is a heat pipe.

According to the first aspect of the present invention, since at least one of the transport rollers has a heat pipe structure, the original placing plate heated by the light source conducts heat transfer with the transport roller having the heat pipe structure. As a result, the temperature of the document placing plate can be efficiently prevented from rising due to the cooling. Thus, when the user uses the so-called pressure plate mode in which the originals are manually placed one by one on the exposure table, the user can perform the operation without feeling hot.

According to a second aspect of the present invention, in the first aspect of the present invention, the original reference transport roller located on the standby position side of the light source of the optical device comprises a heat pipe.

According to the second aspect of the present invention, the transport roller on the original reference side of the heat pipe structure cools the original placing plate side, which is located at the standby position side of the light source of the optical device and has a particularly high temperature. Therefore, it is possible to most efficiently prevent the temperature of the document placing plate from rising at low cost.

According to a third aspect of the present invention, in the first or second aspect, the heat pipe has a liquid sealed in the hollow pipe, and the hollow pipe has radiating fins. It is characterized by having.

According to the third aspect of the present invention, since the heat pipes have radiating fins, it is possible to efficiently prevent a temperature rise of the document placing plate by applying cooling air.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a document feeder 2 of the present invention.
The document supply device 2 is disposed above the copier body 1. Copying machine body 1
Includes an optical device 7, paper feed cassettes 3a and 3b, a photoreceptor 9, and the like.

The paper feed cassettes 3a and 3b accommodate transfer papers P of different sizes, and the transfer paper P fed from the paper feed cassette 3a or the paper feed cassette 3b is indicated by a thick arrow in FIG. Thus, the sheet is sent to the registration roller 4 and stopped. The registration roller 4 is located near the photoconductor 9.

The document feeder 2 shown in FIG. 1 has a document table 5. From a document bundle set on the document table 5, documents are fed one by one to a document reference side of a document placing plate 6. Sent and stopped.

The optical device 7 is located below the document feeder 2 as shown in FIG. 1, and as shown in FIGS. 1 and 2, the exposure lamp 8, the first mirror 18, the second mirror 19, and the third Mirror 20, fourth mirror 22, cooling fan 23, lens 2
1, etc.

When the exposure lamp 8 moves rightward in FIGS. 1 and 2 from the home position HP, the light of the exposure lamp 8 scans and irradiates the original G on the original placing plate (contact glass) 6. I do. The reflected light from the document G is reflected by the first mirror 18, the second mirror 19, and the third mirror 20, passes through the lens 21, is reflected by the fourth mirror 22, and forms an electrostatic latent image on the photosensitive member 9. Made.

The electrostatic latent image on the photoreceptor 9 is
0, the transfer paper P stopped by the registration roller 4 is again conveyed synchronously, and the electrostatic latent image on the photoconductor 9 is transferred to the transfer paper P side, separated and separated as shown in FIG. After the image is fixed by the fixing device 39 shown in FIG.

The exposure lamp 8 of the optical device 7 shown in FIGS. 1 and 2 is located at the so-called home position HP.
Is when it is located on the left side in the drawing. The heat of the exposure lamp 8 is released from the casing 7 a of the optical device 7 by the rotation of the cooling fan 23.

FIG. 3 shows the document supply device 2. The document supply device 2 includes a document table 5, a call roller 12, an upper separation roller 13, a lower separation roller 14, a pull-out roller 14a, a paper feed motor 11, a transport belt, and the like. 15, an upper discharge roller 16, a lower discharge roller 17, a plurality of transport rollers 24 and 25 for the transport belt 15, a plurality of intermediate rollers 41, and the like.

Between the document table 5 and the conveyor belt 15, a call roller 12, an upper separation roller 13, a lower separation roller 14, a pull-out roller 14a, and a paper feed motor 11 are arranged. The transport belt 15 is rotated endlessly in the direction of arrow R by a pair of transport rollers 24 and 25 and a plurality of intermediate rollers 41, and converts one document G in the document bundle on the document table 5 into a document. It can be guided on the mounting plate 6.

When a document bundle is placed on the document table 5 and the document bundle is inserted until it hits a slipper claw (not shown), a document set detection sensor (not shown) detects the document G. Next, when the paper feed motor 11 is turned on by pressing the start key of the copier main body 1, the call roller 12 rotates, and the upper separation roller 13 and the lower separation roller 14 move the original G one sheet at a time toward the transport belt 15 side. Paper is fed.

At a certain timing, the feed motor 11
Is turned off and the transport motor is turned on, the transport belt 15 is rotated endlessly in the R direction by the pair of transport rollers 24 and 25, and the original G stops at the designated position at the leading end of the original G. When the exposure lamp 8 scans from the leading end to the trailing end of the document G and emits light, the image forming process starts.

When the exposure is completed, a conveyance motor and a discharge motor (not shown) are turned on by a discharge signal from the copying machine main body 1, and the conveyance belt 15 shown in FIG. The document is discharged by the discharge roller 16 and the lower discharge roller 17, and the next document G is fed.

When the operation speed of the copying machine body 1 shown in FIG. 1 is required to be increased, the scanning movement speed of the exposure lamp 8 of the optical device 7 is also increased, and the scanning frequency of the exposure lamp 8 is increased. It is difficult to prevent the temperature of the document placing plate 6 from rising due to the heat of the exposure lamp 8 using only the cooling fan 23 shown in FIG.

Therefore, in the embodiment of the present invention, a pair of transport rollers 24 and 25 of the document feeder 2 are provided as shown in FIG. Cooling mechanism 50 is employed. That is,
For example, the transport rollers 24 and 25 have the same structure,
The pair of transport rollers 24 and 25 of the document feeder 2 have a heat pipe structure, and the transport rollers 24 and 25 use a right roller shaft 31 and a left roller shaft 33 to support plates 60 and 61.
Are rotatably supported by the bearings 34 and 35.

The length of the right roller shaft 31 is longer than the length of the left roller shaft 33, and the drive gear 30 and a plurality of cooling fins 32 for cooling are fixed to the right roller shaft 31. . The driving gear 30 is the gear 3 of the transport motor 51.
0a, and when the transport motor 51 is driven, the transport rollers 24, 2 are driven via the gear 30a and the drive gear 30.
5 can be rotated.

The pair of transport rollers 24 and 25 are, for example, a so-called heat pipe type, which is a hollow pipe made of, for example, iron having excellent heat conductivity and in which pure water W as a cooling medium is sealed. ing.

The cooling fins 32 of the right roller shaft 31 shown in FIG. 4 have an increased cooling area so that the belt transport rollers 24 and 25 can be cooled more efficiently. Cooling.

The lighting frequency of the exposure lamp 8 increases as the scanning frequency of the exposure lamp 8 of the optical device 7 increases. As a result, the temperature of the document placing plate 6 increases, and the temperatures of the transport rollers 24 and 25 that are in close contact with the transport belt 15 together with the transport belt 15 also increase.

However, the transport roller 2 having the heat pipe structure
4 and 25, the heat is rapidly radiated from the cooling fins 32, so that the transport belt 15 is also cooled and the transport belt 1 is cooled.
The document placing plate 6 that is in contact with 5 is also cooled.

In the embodiment described above, the belt transport roller has the transport roller 24 on the reference side of the original and the transport roller 25 on the leading end of the original.
5 adopts a heat pipe structure.

On the other hand, as the number of heat transfer rollers having a heat pipe structure increases, the cooling effect of the document placing plate 6 increases. However, when cost reduction is taken into consideration, any one of the transfer rollers 24 and 25 is required. Alternatively, a heat pipe structure may be adopted. For example, the temperature of the document mounting plate 6 where the temperature rises most is the portion on the home position HP side where the exposure lamp (light source) 8 shown in FIGS. 2 and 3 is turned on. When viewed, it corresponds to the document reference side. It is sufficient that only the transport roller 24 on the original reference side has the above-described heat pipe structure, and it is the most advantageous in terms of cost to radiate heat in this manner.

Because the exposure lamp 8 of the optical device 7 does not move for a while after the exposure lamp 8 is turned on, the standby position (home position) HP of the exposure lamp 8 of the optical device 7 is set.
Side temperature is particularly high. However, since the transport roller 24 on the original reference side of the heat pipe structure can efficiently cool the original reference side portion of the original placing plate 6, the temperature rise of the original placing plate 6 can be prevented most efficiently at low cost.

As described above, in the embodiment of the present invention, the original is supplied one by one onto the original placing plate by moving the belt by the transport roller, and the optical device is placed on the original on the original placing plate. In the document feeder configured to irradiate light from the light source to read the contents of the document, at least one transport roller is formed of a cooling hollow body. Preferably, the transport roller has a transport roller on the document reference side and a transport roller on the leading end side of the document, and the transport roller on the document reference side of the transport rollers is located on the standby position side of the light source of the optical device;
The transport roller on the document reference side has a heat pipe structure for cooling, and more preferably, the heat pipe is provided with fins for heat radiation.

By the way, the present invention is not limited to the above embodiment, and various modifications are possible. For example, although the document supply device 2 is applied to the copying machine main body 1, it can be applied not only to the copying machine but also to other types of image forming devices such as a facsimile and a printer.

As the heat pipe structure of the transport roller,
Instead of putting pure water into the pipe, another kind of liquid can be sealed, and the liquid may be circulated from outside as well as the liquid.

[0038]

According to the first aspect of the present invention, since at least one of the transport rollers has a heat pipe structure, the original placing plate heated by the light source contacts and transfers heat with the transport rollers having the heat pipe structure. As a result, the temperature of the document placing plate can be efficiently prevented from rising.
Thereby, when using in the so-called pressure plate mode, the user can work without feeling hot.

According to the second aspect of the present invention, the transport roller on the original reference side of the heat pipe structure can cool the original placing plate side, which is located at the standby position side of the light source of the optical device and has a particularly high temperature, so that The temperature rise of the document placing plate can be prevented most efficiently at low cost.

According to the third aspect of the present invention, since the heat pipe has the fins for radiating the heat, the temperature rise of the original placing plate can be prevented efficiently by applying the cooling air.

[Brief description of the drawings]

FIG. 1 is a front view showing a copying machine main body including a document supply device according to the present invention.

FIG. 2 is a diagram illustrating a document supply device, an optical device, and the like of the copying machine of FIG. 1;

FIG. 3 is a diagram illustrating a document supply device of the copying machine of FIG. 1;

FIG. 4 is a diagram illustrating a belt conveyance roller of the document supply device.

[Explanation of symbols]

 2 Document Feeding Device 6 Document Placement Plate 7 Optical Device 8 Exposure Lamp (Light Source) 15 Conveying Belt (Belt) 24 Conveying Roller (Document Conveying Roller on Reference Side) 25 Conveying Roller (Document Conveying Roller on Top of Document) 24a, 25a Pipe G Manuscript W Pure water (liquid)

Claims (3)

[Claims] An original is supplied one by one from an original plate onto an original placing plate by moving a belt by a plurality of conveying rollers, and light from a light source of an optical device is applied to the original on the original placing plate. A document supply device for irradiating and reading the contents of a document, wherein at least one of the plurality of conveyance rollers is a heat pipe. 2. The document supply device according to claim 1, wherein the document reference side transport roller located on the standby position side of the light source of the optical device comprises a heat pipe. 3. The document supply device according to claim 1, wherein the heat pipe has a liquid sealed in the pipe, and the pipe has a fin for heat radiation.