JPH10254076A - Original image reading device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the original image reading device capable of easily removing matter attached and clung to the upper surface of a contact glass and reducing cleaning times of the contact glass by providing at least the upper surface of the contact glass, on which the original is placed, with a photocatalyst layer. SOLUTION: All the upper surface of the contact glass 3 is provided with the thin photocatalyst layer 15 formed by a chemical vapor deposition so as to cause no trouble in reading the original P. This photocatalyst layer 15 comprises a substance allowing an organic compound to adsorb an oxygen atom or to desorb it when it is irradiated with light, especially, ultraviolet rays, and to accelerate oxidation decomposition. The layer 15 generates electrons and holes and this hole transfer causes electron transfer reaction on the surface and this hole can draw out an electron (oxidizing power) and the matter clung to the surface of the layer 15 is oxidized decomposed and wiped off with dry cloth.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document image reading device for a scanner or a copying machine, and more particularly, to a document image reading device for removing stains on the upper surface of a contact glass.

[0002]

2. Description of the Related Art In a document image reading apparatus such as a scanner or a copying machine, dust or dirt is scattered in the apparatus during use and adheres to the inner surface of a contact glass, so that good document image information can be obtained. May not be obtained. Moreover, since the inner surface of the contact glass in such a device is not easily accessible from outside the device,
It is difficult for the user to care. Therefore,
Japanese Utility Model Publication No. 7-31246 and Japanese Utility Model Application Laid-Open No. 63-8416.
In Japanese Patent Publication No. 3 (2003), a cleaning member is brought into contact with the inner surface of the contact glass, and while maintaining this state, the cleaning member is moved along the contact glass to form an inner surface (lower surface) of the contact glass.
Are disclosed, respectively.

When an original is placed on the upper surface of the contact glass, the original is not completely dried.
If the correction liquid or the like has adhered, a part of them may adhere to the contact glass from the document. Further, when an operator places a document on the upper surface of the contact glass, the operator's hand often touches the upper surface of the contact glass, and sebum or the like of the hand may adhere to the upper surface of the contact glass. These attachments may be recognized as a part of the original image when reading the original image, and good original image information may not be obtained. Further, even if the attached matter is not recognized as a part of the original image, as the reading is repeated, paper dust and dust adhere to the attached matter, and gradually become clear stains. In some cases, the document image is recognized as a part of the document image, and good document image information cannot be obtained. Therefore, an apparatus for detecting dirt on the upper surface of the contact glass is disclosed in Japanese Utility Model Laid-Open No. 63-2941.

Further, Japanese Patent Application Laid-Open No. 8-273631 discloses a copying machine in which a halogen lamp having a photocatalyst film is applied to a light source section used for reading an original image. For example, even if the copying operation is repeatedly performed, the surface of the halogen lamp can be kept clean.

[0005]

As described above, an apparatus for cleaning the lower surface of the contact glass and an apparatus for detecting dirt on the upper surface of the contact glass have been proposed, but the upper surface of the contact glass is cleaned. Regarding that, they still rely on cleaning by workers. That is, in order to obtain good document image information, it is necessary to clean the contact glass by wiping the dirt on the upper surface of the contact glass with a cloth or the like. However, even if the top surface of the contact glass is wiped with a dry cloth, it is not easy to remove deposits such as an adhesive, a correction liquid, and a sebum stain. To completely remove these deposits, a commercially available OA is required. It is necessary to clean using a cleaner or a glass cleaner together, and the cleaning is troublesome.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a document image reading apparatus capable of easily removing the deposits on the upper surface of the contact glass and reducing the number of times of cleaning the upper surface of the contact glass.

[0007]

According to the first aspect of the present invention,
In a document image reading apparatus including a contact glass on which a document is placed, a document pressing member that covers a surface of the contact glass, and a light source unit for document illumination, at least an upper surface of the contact glass on which the document is placed. This is a configuration in which a photocatalyst layer is provided.

According to a second aspect of the present invention, there is provided a document image reading apparatus including a contact glass on which a document is placed, a document pressing member for covering a surface of the contact glass, and a light source for document illumination. The glass has an ultraviolet transmitting property, a photocatalyst layer is provided on a surface of the document pressing member that comes in contact with the contact glass, and when the photocatalyst layer is in contact with the contact glass, light source unit control means for turning on the light source unit is provided. It is a configuration to have.

According to a third aspect of the present invention, there is provided a document image reading apparatus including a contact glass on which a document is placed, a document pressing member for covering the surface of the contact glass, and a light source for document illumination. A photocatalytic layer is provided on at least the upper surface of the glass on which the original is placed and the surface of the original pressing member that contacts the contact glass,
When the photocatalyst layer is in contact with the contact glass, a light source unit control unit for turning on the light source unit is provided.

According to a fourth aspect of the present invention, in the document image reading apparatus according to the first, second, or third aspect, the contact glass has an ultraviolet transmitting property.

The invention according to claim 5 is the invention according to claims 1, 2, 3
In the document image reading device described in Item 4, the light source unit irradiates substantially the entire surface of the contact glass.

[0012] The invention according to claim 6 is the invention according to claims 1, 2, and 3.
In the document image reading device according to 3, 4, or 5, the member covering the light source of the light source unit has a configuration that has ultraviolet transmittance.

The invention according to claim 7 is based on claims 1, 2, and
In the document image reading apparatus described in 3, 4, 5, or 6,
The document image reading apparatus is provided inside a housing of the document image reading apparatus, and includes an ultraviolet ray generating light source for irradiating the photocatalyst layer with ultraviolet rays, and ultraviolet ray generating light source control means for controlling the ultraviolet ray irradiation by the ultraviolet ray generating light source.

According to an eighth aspect of the present invention, in the original image reading apparatus according to the seventh aspect, the ultraviolet light generation light source control means emits ultraviolet light from the ultraviolet light source only when the contact glass is covered with the original pressing member. Configuration.

The invention according to claim 9 is the invention according to claim 7 or 8.
In the document image reading device described above, when the document image reading device is waiting for document reading, the ultraviolet ray generation light source control means performs ultraviolet irradiation by an ultraviolet ray generation source.

The invention according to claim 10 is the invention according to claims 1, 2, and
3. The document image reading device according to 3, 4, 5, 6, 7, 8 or 9, wherein the main component of the photocatalytic layer is anatase type titanium dioxide.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to the drawings. In FIG. 1, reference numeral 1 denotes a copying machine. A document image reading device 2 is provided above the copying machine 1.
The document image reading device 2 mainly includes a contact glass 3, a document pressing member 4, and an optical system 5. The document pressing member 4 is supported so as to be openable and closable with respect to the main body of the copying machine 1, and covers the upper surface of the contact glass 3 when reading a document, and presses the document on the contact glass 3. The optical system 5 is disposed below the contact glass 3, and includes a lamp unit 6 as a light source unit, and mirrors 7 a to 7.
d and a lens 8.

Lamp unit 6 and mirrors 7a to 7c
The scanning and lighting are controlled by a not-shown lamp unit control unit as a light source unit control unit, and are relatively moved with respect to the contact glass 3 at the time of reading a document, thereby being placed on the contact glass 3. A predetermined portion of the photoconductor 12 is irradiated with an image of the document. The lamp unit 6 includes a document illumination lamp 9 as a light source, a reflector 10 and a bracket 11 for supporting these. Although a halogen lamp is used as the document illumination lamp 9, a fluorescent lamp may be used instead of the halogen lamp.

As shown in FIG. 2, a photocatalyst layer 15 is provided on the entire upper surface of the contact glass 3. The photocatalyst layer 15 is formed in a thin film shape by a chemical vapor deposition method so as not to hinder reading of the document P. As a method for forming the photocatalyst layer 15 into a thin film,
Neutralization or hydrolysis of an inorganic metal salt, hydrolysis of a metal alkoxide, or a sol-gel method may be used.

The photocatalyst layer 15 is made of a substance that, when irradiated with light, especially ultraviolet rays, adsorbs or desorbs oxygen molecules to an organic compound and exhibits a function of promoting oxidative decomposition. As this substance, TiO ₂ (titanium dioxide), V ₂ O ₅ (vanadium pentoxide), ZnO (zinc oxide), WO ₃ (tungsten trioxide) and the like are known. Among them, crystalline anatase TiO _2, which is known to have a particularly high efficiency as a photocatalyst, is used as a main component. In forming the photocatalyst layer 15, two or more of the above substances may be mixed, or platinum, palladium, rhodium, niobium or the like, which is known to further promote the photocatalytic reaction, may be mixed. Is also good.

Next, the operation of the contact glass 3 will be described. When the document P is repeatedly placed on the contact glass 3, glue, an adhesive, a correction liquid, and a sebum adhered to the document P adhere to the upper surface of the photocatalyst layer 15. These are organic compounds.
The glue, the adhesive, the correction liquid, and the sebum of the hand attached to the upper surface of the photocatalyst layer 15 are collectively referred to as attached matter.

In order to remove the extraneous matter, first, when the document image reading device 2 is in a reading standby state, that is, when the document P is not being read, the document pressing member 4 is opened.
Maintain this state. When the document pressing member 4 is opened, light from the outside of the document image reading device 2, that is, light from a fluorescent lamp in the room irradiates the photocatalytic layer 15.
Ultraviolet light is also contained in a fluorescent lamp used for indoor lighting, and this ultraviolet light causes electrons and holes (holes) for electrons in the photocatalytic layer 15, and the movement of the holes causes an electron transfer reaction on the surface thereof. . At this time, the holes have the power to draw out electrons (oxidizing power),
Due to the oxidizing power of the holes, the deposits in contact with the photocatalyst layer 15 are oxidized and decomposed. The oxidatively decomposed deposit is
It can be easily removed by wiping with a dry cloth. Light sebum dirt is almost completely oxidatively decomposed and does not need to be wiped off.

Therefore, on the upper surface of the contact glass 3, the sediment adhered to the sebum is almost completely oxidatively decomposed by the photocatalytic reaction of the photocatalyst layer 15, and the adhering matter such as the glue, the adhesive and the correction liquid is removed Since it is easily removed by wiping the upper surface, the upper surface of the contact glass 3 can be easily cleaned, and the number of times of cleaning can be reduced. In addition, since the attached matter on the upper surface of the contact glass 3 is almost completely removed, good original image information can be obtained.

Next, a second embodiment will be described. The configuration of the document image reading apparatus 2 in this embodiment is shown in FIGS.
2 is substantially the same as the original image reading apparatus 2 shown in FIG. 2, the original image reading apparatus 2 of the present embodiment will be described with reference to FIGS. In the above-described embodiment, if the document pressing member 4 is opened, dust scattered in the room may accumulate on the upper surface of the contact glass 3. When the indoor environment is extremely poor, that is, when a large amount of dust is scattered in the room, the amount of dust accumulated on the upper surface of the contact glass 3 increases, and it becomes difficult to obtain good document image information. There is. Therefore, in the second embodiment, a photocatalytic reaction is caused in the photocatalyst layer 15 by using the light of the document illumination lamp 9 that illuminates the image surface of the document P when reading the document. A halogen lamp is used as the document illumination lamp 9.
This halogen lamp also contains ultraviolet rays.

Normally, the original illumination lamp 9 scans and illuminates the original P. However, instead of scanning the entire surface of the contact glass 3, the scanning amount of the original illumination lamp 9 is controlled in a designated area, original size. Is performed on the basis of the area corresponding to the image size and the area corresponding to the output paper size. Therefore, a region where light is not irradiated may occur on the photocatalyst layer 15, and a photocatalytic reaction does not occur in the region where light is not irradiated.
Therefore, in the present embodiment, a program for scanning the entire surface of the contact glass 3 when reading a document is stored in the lamp unit control means. When the document P is illuminated by the lamp unit control means, the document illumination lamp 9 scans the entire surface of the contact glass 3.

On the other hand, the contact glass 3 has, on its surface, a photorefractive index layer made of a mixture of TiO ₂ (titanium dioxide) and Fe ₂ O ₃ (diiron trioxide), and SiO ₂ (silicon dioxide) as a main component. It is formed of a glass not provided with an ultraviolet cut filter film formed by laminating a low refractive index layer described above. That is, the contact glass 3
Is made of ultraviolet transmitting glass and has a property of transmitting ultraviolet light. Note that, instead of the ultraviolet transmitting glass, a special glass in which iron oxide contained as an impurity is suppressed to 0.01% or less and the ultraviolet transmittance is increased may be used.

When reading the original, the illumination lamp 9 is turned on by the control of the lamp unit control means.
Is scanned over the entire surface. Therefore, the contact glass 3 is illuminated from its inner surface by the document illumination lamp 9. Since the contact glass 3 is formed of an ultraviolet transmitting glass, the ultraviolet light included in the irradiation light from the halogen lamp reaches the photocatalyst layer 15. The photocatalyst layer 15 causes the above-described photocatalytic reaction by the ultraviolet rays, and oxidizes and decomposes the deposits in contact with the photocatalyst layer 15. Therefore, even when the document pressing member 4 is in the closed state, the attached matter on the upper surface of the contact glass 3 is oxidized and decomposed by the photocatalytic reaction of the photocatalytic layer 15 when reading the document, so that a large amount of dust is scattered in the room. In this case, the document holding member 4 can be kept closed, and dust can be prevented from being deposited on the upper surface of the contact glass 3.

The light source portion of the halogen lamp is covered with glass. By forming the glass portion with the above-described ultraviolet transmitting glass, the ultraviolet photocatalyst layer 1 is formed.
5 can be increased, and the photocatalytic reaction can be improved. Even when a fluorescent lamp is used instead of the halogen lamp, the same effect can be obtained by forming this glass portion with the above-described ultraviolet transmitting glass.

Next, a third embodiment will be described with reference to FIG. In the figure, the same members as those shown in FIG. 1 are denoted by the same reference numerals as those used in FIG. 1, and the description thereof will be omitted, and different points will be described. In the second embodiment, the document illumination lamp 9 is turned on only when reading a document. Therefore, depending on the use situation, the irradiation time of the ultraviolet light to the photocatalyst layer 15 may be too short to perform the photocatalysis sufficiently. Therefore, in the third embodiment, a light source for generating ultraviolet light is provided separately from the document illumination lamp 9.

The details will be described below. As shown in FIG.
Inside the housing of the document image reading device 2, an ultraviolet lamp 20 as an ultraviolet light source independent of the document illumination lamp 9 is provided at a position where the lamp unit 6 and the mirrors 7a to 7c do not interfere with the movement even if they move. It is arranged. The ultraviolet lamp 20 is fixed to a side plate of a housing of the document image reading device 2 via a bracket 21. The UV lamp 20 has a low output in consideration of safety for workers,
Generates near-ultraviolet light having a wavelength of 300 nm or more, and
A lamp capable of irradiating the entire surface of the contact glass 3 at once is used. In other words, a lamp that emits substantially the same ultraviolet light as the ultraviolet light emitted by the document illumination lamp 9 is used. The ultraviolet lamp 20 is connected to ultraviolet lamp control means as ultraviolet light source control means, and its lighting is controlled by the ultraviolet lamp control means.

When the original image reading device 2 is in a standby state for reading an original, that is, when no operation is performed even after a lapse of a predetermined time from the end of the original reading, the ultraviolet lamp control means controls the ultraviolet lamp. 20 is turned on for a predetermined time. When the standby state is a long time, the ultraviolet lamp control means turns on the ultraviolet lamp 20 for a predetermined time at regular intervals. As described above, when the document image reading device 2 is in the standby state, that is, when each part of the document image reading device 2 is not operating, the ultraviolet lamp 20 is turned on to temporarily stop the document image reading device 2. An increase in power consumption can be suppressed.

Next, a fourth embodiment will be described.
This embodiment is different from the third embodiment in that the ultraviolet lamp 2
0, a lamp having a higher output than the document illumination lamp 9 is used. As the ultraviolet lamp 20 in the third embodiment, a low output lamp is used in consideration of safety for workers. However, since the photocatalytic reaction becomes more active as the output of the lamp increases, the UV lamp 20 having a higher output than the original illumination lamp 9 is used when the upper surface of the contact glass 3 is easily stained with an adhesive, a correction liquid, sebum, or the like. It is effective to use.

Therefore, in this embodiment, the ultraviolet lamp 20
In addition, a lamp having a higher output than the document illumination lamp 9 is used. However, if the upper surface of the contact glass 3 is not covered with the document P or the document pressing member 4 while the document image reading device 2 is waiting for reading the document, the ultraviolet rays leak to the outside of the document image reading device 2. If the ultraviolet lamp 20 has an ultraviolet output equivalent to the ultraviolet output generated by the document illumination lamp 9, there is no problem in safety even if it leaks to the outside,
In this embodiment, since the ultraviolet lamp 20 having a higher output than the document illumination lamp 9 is used, there is a possibility that a problem may occur in safety.

Therefore, the UV lamp control means limits the lighting of the UV lamp 20 so that the UV lamp 20 is turned on only when the upper surface of the contact glass 3 is covered by the document pressing member 4. A block diagram and a flowchart for performing this control are shown in FIGS. 4 and 5, respectively, and the contents of the control will be described.

In FIG. 4, the ultraviolet lamp control means 30
An opening / closing sensor 31 for detecting that the document pressing member 4 is closed is provided on the input side of the UV lamp 2 on the output side.
0 are respectively connected. The open / close sensor 31 is provided around the contact glass 3 and is turned on when the document pressing member 4 is closed. Then, the ultraviolet lamp control unit 30 performs control according to the flowchart.

First, in step A1, it is determined whether a state in which no operation has been performed for a predetermined time has elapsed after the document reading is completed. If the predetermined time has elapsed, the process proceeds to step A2. If the predetermined time has not elapsed, or if any operation has been performed, the process returns to step A1. In step A2, the opening and closing of the document pressing member 4 is detected. When the open / close sensor 31 is on, the document pressing member 4
Is determined to be closed and the process proceeds to step A3. If the open / close sensor 31 is off, it is determined that the document pressing member 4 is open and the process returns to step A1. Step A3
Then, the ultraviolet lamp 20 is turned on for a predetermined time, and after the lapse of the predetermined time, the ultraviolet lamp 20 is turned off, and the process returns to step A1.

As described above, since the ultraviolet lamp 20 is turned on only when the upper surface of the contact glass 3 is covered with the document pressing member 4, safety can be ensured and the photocatalytic reaction of the photocatalytic layer 15 can be more activated. The deposits on the upper surface of the contact glass 3 can be further oxidatively decomposed.

Further, regarding the fifth embodiment, FIGS.
This will be described with reference to FIG. This embodiment is different from the fourth embodiment only in that a photocatalyst layer is also provided on the original pressing member 4 side, and other configurations are the same. Only the points to be performed will be described.

As shown in FIGS. 6 and 7, when there is no original P on the contact glass 3 and the original pressing member 4 is closed, the surface of the original pressing member 4 which contacts the contact glass 3 has a photocatalyst. A layer 16 is provided. The photocatalyst layer 16 is formed into a thin film by a chemical vapor deposition method similarly to the photocatalyst layer 15, and is made of the same material as the photocatalyst layer 15.

The contact glass 3 is formed by the photocatalyst layer 16.
In order to oxidatively decompose the deposit on the upper surface of the photocatalyst layer 16
Needs to be in contact with the upper surface of the contact glass 3. Therefore, control is performed to turn on the ultraviolet lamp 20 when the upper surface of the contact glass 3 is covered with the document pressing member 4 and there is no document P on the contact glass 3. A block diagram and a flowchart for performing this control are shown in FIGS. 8 and 9, respectively, and the contents of the control will be described.

In FIG. 8, the ultraviolet lamp control means 30
An open / close sensor 31 for detecting that the document pressing member 4 is closed and a document presence / absence sensor 33 for detecting that there is no document P on the upper surface of the contact glass 3 are respectively connected to the input side of. An ultraviolet lamp 20 is connected to the output side. The document presence sensor 33 is turned on when the document P is placed on the upper surface of the contact glass 3. Then, the ultraviolet lamp control unit 30 performs control according to the flowchart.

Steps A1 and A2 are the same as steps A1 and A2 in FIG. 5, and a description thereof will be omitted. If the open / close sensor 31 is on in step A2, the process proceeds to step A21. In step A21,
It is detected whether or not the document P is placed on the upper surface of the contact glass 3. If the document presence 33 is off, it is determined that the document P is not placed on the upper surface of the contact glass 3, and the process proceeds to step A3. move on. If the document presence / absence 33 is off, it is determined that the document P is placed on the upper surface of the contact glass 3, and the process returns to step A1. In step A3, the ultraviolet lamp 20 is turned on for a predetermined time, and after the lapse of the predetermined time, the ultraviolet lamp 20 is turned off, and the process returns to step A1.

As described above, the ultraviolet lamp 20 is turned on only when the upper surface of the contact glass 3 is covered by the document pressing member 4 and there is no document P on the contact glass 3. 16 photocatalytic reactions can be activated and safety can be ensured. Further, the deposits on the upper surface of the contact glass 3 are oxidized and decomposed from above and below, so that the upper surface of the contact glass 3 can be easily cleaned.

In the present embodiment, the ultraviolet irradiation means is constituted by the ultraviolet lamp 20. However, the ultraviolet irradiation means is constituted by the document illumination lamp 9 instead of the ultraviolet lamp 20, and the entire surface of the contact glass 3 is scanned. You may.

In the above-described first to fifth embodiments, the contact glass of the original image reading device of the copying machine has been described. However, even when the photocatalyst layer is provided on the contact glass of the scanner, the first to fifth embodiments can be performed. It goes without saying that the same effect as the effect obtained by the example can be obtained. In addition, by providing the photocatalyst layer also on the inner surface of the contact glass, dirt on the inner surface of the contact glass can be oxidized and decomposed, thereby preventing the inner surface of the contact glass from being stained.

[0046]

As described above, according to the first aspect of the present invention, since the photocatalyst layer is provided on the upper surface of the contact glass, the organic compound adhering to the photocatalyst layer can be removed. The surface of the contact glass is easily oxidized and decomposed by the photocatalytic reaction by irradiating the surface of the contact glass with ultraviolet light, so that the number of times of cleaning the upper surface of the contact glass can be reduced, and good document image information can be obtained.

According to the second aspect of the present invention, since the photocatalyst layer is provided on the surface of the document holding member that comes into contact with the contact glass, the organic compound adhering to the photocatalyst layer can be prevented from being adhered to the photocatalyst layer by ultraviolet rays. Irradiates the surface of the contact glass with a photocatalytic reaction, so that the upper surface of the contact glass can be easily cleaned, and good original image information can be obtained.

According to the third aspect of the present invention, since the contact glass has ultraviolet transmittance, the ultraviolet light from below the contact glass also reaches the photocatalyst layer, so that the light illuminating the original when reading the original image can be used. Also, at the time of reading an original, it is possible to oxidatively decompose the attached matter, which is an organic compound, attached to the photocatalytic layer by a photocatalytic reaction.

According to the fourth aspect of the present invention, since the light source of the document image reading device irradiates substantially the entire surface of the contact glass, a photocatalytic reaction can be caused on substantially the entire surface of the photocatalyst layer by the light source. In addition, a separate light source dedicated to ultraviolet light is not required, so that cost increase can be suppressed.

According to the fifth aspect of the present invention, since the member covering the light source section has ultraviolet transmittance, it is possible to efficiently supply ultraviolet rays to the photocatalyst layer.

According to the sixth aspect of the present invention, since the photocatalyst layer has an ultraviolet ray generating source for irradiating the photocatalyst layer, the ultraviolet ray can be efficiently supplied to the photocatalyst layer. The deposit can be reliably oxidized and decomposed by the photocatalytic reaction.

According to the seventh aspect of the present invention, only when the contact glass is covered with the document pressing member, the ultraviolet ray is irradiated from the ultraviolet ray generating source, so that safety for the worker can be ensured.

According to the eighth aspect of the present invention, when the original image reading apparatus is in a standby state for reading the original, the ultraviolet irradiation is performed by the ultraviolet light source. An increase in power can be suppressed.

According to the ninth aspect of the present invention, since the photocatalyst layer is provided on the upper surface of the contact glass and on the surface of the document pressing member that comes into contact with the contact glass, the organic compound adheres to the photocatalyst layer. Since the attached matter is oxidatively decomposed by a photocatalytic reaction caused by irradiating the photocatalyst layer with ultraviolet light, the upper surface of the contact glass can be easily cleaned, and good original image information can be obtained.

According to the tenth aspect of the present invention, the main component of the photocatalyst layer is anatase-type titanium dioxide. It can be oxidatively decomposed by the reaction.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a document image reading apparatus of a copying machine according to first and second embodiments of the present invention.

FIG. 2 is an enlarged sectional view of a partly broken contact glass in FIG.

FIG. 3 is a schematic configuration diagram of a document image reading apparatus of a copying machine showing a third embodiment of the present invention.

FIG. 4 is a block diagram of an ultraviolet lamp control unit according to a fourth embodiment of the present invention.

FIG. 5 is a flowchart illustrating control for turning on an ultraviolet lamp according to a fourth embodiment of the present invention.

FIG. 6 is a schematic configuration diagram of a document image reading device of a copying machine showing a fifth embodiment of the present invention.

FIG. 7 is an enlarged cross-sectional view of the contact glass in FIG.

FIG. 8 is a block diagram of an ultraviolet lamp control unit according to a fifth embodiment of the present invention.

FIG. 9 is a flowchart illustrating control for turning on an ultraviolet lamp according to a fifth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Copier 2 Document image reading device 3 Contact glass 4 Document holding member 6 Lamp unit 9 Document illumination lamp 15, 16 Photocatalytic layer 20 Ultraviolet lamp 30 Ultraviolet lamp control means 31 Open / close sensor 32 Document presence sensor P Document

Claims (10)

[Claims] 1. A document image reading apparatus comprising: a contact glass on which a document is placed; a document pressing member for covering a surface of the contact glass; and a light source for document illumination. A document image reading device, wherein a photocatalyst layer is provided on an upper surface on which the document is placed. 2. A document image reading apparatus comprising: a contact glass on which a document is placed; a document pressing member for covering the surface of the contact glass; and a light source for illuminating the document. A light source unit control unit for turning on the light source unit when a photocatalyst layer is provided on a surface of the document pressing member that is in contact with the contact glass; and when the photocatalyst layer is in contact with the contact glass. A document image reading device comprising: 3. A document image reading apparatus comprising: a contact glass on which a document is placed; a document pressing member for covering a surface of the contact glass; and a light source unit for illuminating the document. A photocatalyst layer is provided on an upper surface on which the document is placed and a surface of the document pressing member that contacts the contact glass, and a light source unit that turns on the light source unit when the photocatalyst layer is in contact with the contact glass. A document image reading device comprising a control unit. 4. The original image reading apparatus according to claim 1, wherein said contact glass has an ultraviolet transmittance. 5. An original image reading apparatus according to claim 1, wherein said light source irradiates substantially the entire surface of said contact glass. 6. A member for covering the light source of the light source section has ultraviolet transmittance.
4. The document image reading device according to 4 or 5. 7. An ultraviolet light source provided inside a housing of the document image reading device for irradiating the photocatalyst layer with ultraviolet light, and an ultraviolet light source control means for controlling ultraviolet light irradiation by the ultraviolet light source. The document image reading apparatus according to claim 1, 2, 3, 4, 5, or 6, wherein 8. An original image according to claim 7, wherein said ultraviolet light source control means performs ultraviolet irradiation by said ultraviolet light source only when said contact glass is covered with said original pressing member. Reader. 9. An original according to claim 7, wherein said ultraviolet ray generating light source control means irradiates an ultraviolet ray from said ultraviolet ray generating source when said original image reading apparatus is in standby for reading an original. Image reading device. 10. The photocatalytic layer according to claim 1, wherein a main component of said photocatalytic layer is anatase type titanium dioxide.
A document image reading device according to 3, 4, 5, 6, 7, 8 or 9.