Moisture removal apparatus and method of image read out apparatus

A moisture removal apparatus and method of an image read-out apparatus, in which the image read-out apparatus includes a contact image sensor (CIS) provided with a document glass on which a document is put on an upper portion thereof and a read-out unit to read out an image of the document, and a pressing roller rotatably provided in contact with a top surface of the CIS to press and transfer the document. The moisture removal apparatus includes a heater to heat the document glass at a predetermined temperature to remove moisture, a power source to apply a predetermined voltage to the heater, a sensing unit to provide basic information to determine driving conditions of the heater, and a controller to control heating conditions of the heater on the basis of the information received from the sensing unit. Thereby, the moisture on the top surface of the document glass may be effectively removed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit under 35 U.S.C. §119 of Korean Patent Application No. 2004-48563 filed on Jun. 25, 2004, the disclosure of which is hereby incorporated herein by reference and in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present general inventive concept relates to a moisture removal apparatus and method of an image read out apparatus, and more particularly, to a moisture removal apparatus and method of an image read out apparatus, in which the moisture is prevented from forming on an upper surface of a contact image sensor (CIS), to thereby decrease a paper transfer error.

2. Description of the Related Art

Recently, terminals such as a facsimile, a printer, a copier, a scanner, etc., independently used as office equipment, have been incorporated into a multi-function terminal, such as a multi-function peripheral (MFP).

Such an MFP should read out a document prior to copying the document. A method of reading out the document in the MFP is classified into a contact image sensor (CIS) type and a charged couple device (CCD) type according to an arrangement of a read out element. In the CCD type, pixels read out by a light source (e.g., a fluorescent lamp or a light emitting diode (LED)) corresponding to one line are concentrated through a mirror or lens, and thus thousands of read out elements corresponding to one line are converted into electrical signals through the CCD. In the CIS type, a light source (usually LED) and a read out sensor are integrated into one, and then brought into contact with a document to read out the document. Recently, the CIS type has been widely used.

Such a CIS is disclosed in U.S. Pat. No. 5,214,273 (issued on May 25, 1993).

In this disclosure, there is a main frame, over which a glass cover is covered. The main frame is provided with a light source, which emits light toward the glass cover. A rod lens array is provided on one side of the light source and condenses the light which is emitted from the light source and reflected from a predetermined position of the glass cover. A photo converter element is provided under the rod lens array and receives the condensed light.

Further, a document read-out apparatus employing this CIS is disclosed in Japanese publication No. 09-55828, published on Feb. 25, 1997.

This document read-out apparatus includes a CIS, a CIS roller contacting a document glass and transferring a document in contact with the document glass, a motor driving the CIS roller to operate, and so forth.

In such a document read-out apparatus, the surface of the document glass may become damp due to an ambient temperature difference. When moisture forms on the document glass, a problem occurs in which the document paper adheres to the document glass, and thereby fails to be transferred.

Particularly, photo paper having minute surface roughness has been recently used for photoprinting or to print a high resolution image such as a photo image. However, the photo paper adheres to the moist document glass more easily, and thus fails to be transferred.

SUMMARY OF THE INVENTION

The present general inventive concept provides a moisture removal apparatus to be used with an image read-out apparatus, in which moisture is prevented from forming on a document glass of a contact image sensor (CIS), to thereby allow paper to be smoothly transferred.

The present general inventive concept also provides a moisture removal method of an image read-out apparatus.

The foregoing and/or other aspects and advantages of the present general inventive concept are achieved by providing a moisture removal apparatus to be used with an image read-out apparatus, in which the image read-out apparatus includes a contact image sensor (CIS) provided with a document glass on which a document is put on an upper portion thereof and a read-out unit to read out an image of the document is provided an inner portion thereof, and a pressing roller rotatably provided in contact with a top surface of the CIS to transfer the document, the moisture removal apparatus including a heater to heat the document glass at a predetermined temperature to remove moisture, a power source to apply a predetermined voltage to the heater, a sensing unit to provide basic information to determine driving conditions of the heater, and a controller to control heating conditions of the heater according to the information received from the sensing unit.

The heater may be provided in the document glass, and can be coated on an inner surface of the document glass. Alternatively, the heater may be provided in the pressing roller.

The sensing unit may include a room temperature sensor which can be mounted to the image read-out apparatus to sense a room temperature to determine the driving conditions of the heater, a humidity sensor to sense humidity of a surface of the document glass to determine the driving conditions of the heater, and a temperature sensor to sense temperature of the document glass to determine the driving conditions of the heater.

The temperature sensor can check whether the temperature of the document glass of the CIS exceeds a driving temperature. Further, the temperature sensor can sense a surface temperature of the document glass.

The moisture removal apparatus may further include a document sensor which is provided to a document feeder of the image read-out apparatus to sense whether the document is fed into the document feeder.

The foregoing and/or other aspects and advantages of the present general inventive concept may also be achieved by providing a method of removing moisture of an image read-out apparatus, the method including sensing whether a document is fed into a document feeder, sensing a humidity of a top surface of a document glass of a CIS, determining driving conditions of a heater to heat the document glass according to the sensed humidity, and driving the heater on the basis of the driving conditions to remove moisture.

The driving conditions of the heater may be given by tabulating a target temperature to drive the heater according to the sensed humidity. Further, the driving conditions of the heater may include keeping the heater substantially at the target temperature for a predetermined amount of time when the heater reaches the target temperature.

The method may further include rechecking the humidity of the top surface of the document glass after removing the moisture to determine the driving conditions of the heater to heat the document glass according to the rechecked humidity when the rechecked humidity exceeds a reference humidity, and driving the heater according to the driving conditions to repeatedly remove the moisture.

The method may further include checking the temperature of the CIS after removing the moisture and cooling the CIS to a driving temperature when the checked temperature is greater than the driving temperature of the CIS.

The foregoing and/or other aspects and advantages of the present general inventive concept may also be achieved by providing a moisture removal method of an image read-out apparatus, the method including sensing whether a document is fed into a document feeder, sensing a room temperature at the image read-out apparatus, determining driving conditions of a heater to heat a document glass of a CIS according to the sensed room temperature, and driving the heater according to the driving conditions to remove moisture.

The driving conditions of the heater may be given by tabulating a target temperature to remove the moisture according to the sensed room temperature. Further, the driving conditions of the heater may include keeping the heater substantially at the target temperature for a predetermined amount of time when the heater reaches the target temperature.

The method may further include checking the temperature of the CIS after removing the moisture, and cooling the CIS to a driving temperature when the checked temperature is greater than the driving temperature of the CIS.

The foregoing and/or other aspects and advantages of the present general inventive concept may also be achieved by providing a moisture removal method of an image read-out apparatus, the method including sensing whether a document is fed into a document feeder, sensing a surface temperature of a document glass of a CIS through a temperature sensor, driving a heater until the heater reaches a predetermined target temperature corresponding to the sensed temperature, and checking whether the heater reaches the target temperature.

The driving conditions of the heater may include keeping the heater substantially at the target temperature for a predetermined amount of time when the heater reaches the target temperature.

The method may further include checking the temperature of the CIS after removing the moisture, and cooling the CIS to a driving temperature when the checked temperature is greater than the driving temperature of the CIS.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1is a perspective view illustrating an image read-out apparatus according to an embodiment of the present general inventive concept, andFIG. 2is a cross-sectional view taken along a line I-I′ ofFIG. 1.

Referring toFIG. 1, the image read-out apparatus may include a contact image sensor (CIS)10to read out an image of a document1. A pressing roller30can be rotatably provided in contact with an upper surface of the CIS10so as to transfer the document1. A moisture removal unit50is provided on the upper surface of the CIS10to prevent moisture from being formed on the upper surface of the CIS10due to an ambient temperature difference. In addition, the image read-out apparatus may include a document sensor17to sense whether the document1is fed into a document feeder (not shown). Here, the document sensor17can sense the document1standing by the document feeder (not shown) rather than the document1placed on the CIS10. Hence, the moisture removal unit50can be prevented from unnecessarily operating in a state in which the document1is not ready to be fed.

Referring toFIGS. 1 and 2, the CIS10may include a main frame11, a document glass13covering an upper side of the main frame11, and a read-out unit15to read out an image of the document1placed on the document glass13.

The read-out unit15may include a light source15ato emit light toward the document glass13, a lens array15bprovided on one side of the light source15ato condense the light emitted from the light source and reflected from a predetermined position P of the document1, and a photo converter element15cprovided under the lens array15bto form the condensed light into an image. Here, information on the document1can be detected by the photo converter element15cand converted into an image signal as an analog signal. Thus, the read-out unit15can read out the information on the document1.

The moisture removal unit50heats the document glass13at a predetermined temperature and removes the moisture from a surface of the document glass13. The moisture removal unit50can include a heater51provided in the document glass13to heat the document glass13at a predetermined temperature, a power source53to apply a predetermined voltage to the heater51, a sensing unit57to sense the moisture of the document glass13and to provide guidance in a selection of conditions to drive the heater51, and a controller55to determine driving conditions of the heater51according to information received from the sensing unit57and to transmit a driving signal to the heater51.

The sensing unit57may include various devices, such as a temperature sensor57ato sense a surface temperature of the document glass13of the CIS10, a humidity sensor57bto sense humidity of the surface of the document glass13of the CIS10, and a room temperature sensor57cto sense an ambient room temperature. The room temperature sensor57ccan be mounted to the image read-out apparatus in which the CIS10is provided.

Therefore, the driving conditions of the heater51can be determined on the basis of information sensed by the temperature sensor57a, the humidity sensor57b, or the room temperature sensor57c, and thus the heater51can be driven to remove the moisture, which will be described in detail below.

Meanwhile, in a state in which the temperature of the CIS10exceeds a driving temperature while the heater51generates heat to remove the moisture, the CIS10may not be driven. Therefore, it can be required to check the driving temperature of the CIS10. At this time, the temperature sensor57acan sense whether the CIS10maintains the driving temperature. If the temperature of the CIS10exceeds the driving temperature, the CIS10can experience cooling until its temperature arrives at the driving temperature. For example, the temperature satisfying the conditions to drive the CIS10can range from about 15° C. to about 35° C. Further, the temperature sensor57achecks the temperature of the document glass13, and then not only can provide information to determine a quantity of the heat generated from the heater51, but also can check whether the CIS10maintains the driving temperature. Further, the temperature sensor57acan check the surface temperature of the document glass13.

Hereinafter, a configuration of the heater51will be described in more detail.

The heater51may include an opaque heater51acoated on an inner surface of the document glass13. Here, the opaque heater51acan be placed, for example, on an edge of the document glass13so as not to interfere with the read-out unit15.

Meanwhile,FIG. 3illustrates a transparent heater51bused as the heater51, by way of example. Referring toFIG. 3, the heater51may include the transparent heater51b. In this case, the transparent heater51bdoes not interfere with the read-out unit15, so the transparent heater51bcan be coated on the inner surface of the document glass13at predetermined intervals regardless of its position. The transparent heater51bmay include a material having a good conductivity and keeping transparency, for example, indium oxide, zinc oxide, tin oxide, etc. The above materials are naturally transparent enough so as not to interfere with the read-out unit15.

Further, the heater51can be a conductor having a resistance R and generating heat when electric current flows therein. For example, the heater51can have a resistance R of 100Ω or more.

In the foregoing description, the heater51is provided in the document glass13and directly heats the document glass13. However, the heater51may be strategically placed so as to indirectly heat the document glass13.

FIG. 4illustrates a heater51′ provided in the pressing roller30, andFIG. 5is a cross-sectional view taken along the line II-II′ ofFIG. 4.

Referring toFIGS. 4 and 5, the heater51′ is provided in the pressing roller30and indirectly heats the document glass13in contrast with the heater51ofFIGS. 1 and 2provided in the document glass13and directly heats the document glass13.

In this embodiment, like numbers as inFIG. 1refer to like elements, and their detailed descriptions will therefore be omitted. Referring toFIGS. 4 and 5, the heater51′ operates on the same principle as the heater51ofFIGS. 1 and 2.

Hereinafter, a description will be made about a method of removing the moisture using the moisture removal unit50of an image read-out apparatus configured as described above.

When a user instructs the image read-out apparatus to read out an image, the document glass13is heated at a predetermined temperature to remove the moisture of the document glass13before the CIS10starts reading out the image.

FIG. 6is a flowchart illustrating a process of removing the moisture through the humidity sensor57bof the moisture removal unit50.

Referring toFIG. 6, a method of reading out an image can include sensing whether the document1is fed, at operation S30, removing the moisture, at operation S100, and reading out an image, at operation S50.

In the operation S30of sensing whether the document1is fed, the document1can be fed into the document feeder, and an automatic feeding unit can transfer the document1sheet by sheet. At this time, the document sensor17senses whether the document1is fed. When the document1is sensed, the document1can be placed in a standby state. The standby state can be maintained in order to get either a facsimile number input by a user when the user intends for facsimile transmission, or an instruction of conditions, etc., which the user requires in order to copy or scan the document.

Here, a signal from the document sensor17can play an important role in determining whether the operation S100of removing the moisture is performed or not. That is, when the document is not sensed by the document sensor17, the operation S100of removing the moisture is not performed. This is to prevent the operation S100of removing the moisture from being unnecessarily performed in a state in which the document1is not fed.

Consequently, the operation S100of removing the moisture can be performed while the document is maintained in the standby state as set forth above, and its detailed process is as follows.

The operation S100of removing the moisture can include sensing the humidity of the surface of the document glass13of the CIS10, at operation S110, determining the driving conditions of the heater51when a value of the sensed humidity is greater than a value of a reference humidity, at operation S120, and driving the heater51on the basis of the determined driving conditions of the heater51and checking whether the heater51reaches a driving target temperature, at operation S130.

Here, the driving conditions of the heater51can be determined by tabulating values of the target temperatures to drive the heater51corresponding to the value of the humidity sensed in operation S110. Then, the corresponding driving condition can be adapted to be applied.

Table 1 shows an example of a table to determine the driving conditions. A detailed description will be made about a process of determining the driving conditions.

When the humidity sensed in the operation S110is 35%, the controller55can select the driving mode “A” in the determination table of Table 1 and transmit a driving signal to the heater51. In mode “A”, the heater51is heated at the target temperature of 25° C. to remove the moisture. Further, the temperature of 25° C. is maintained for a time of 0.1 second, to thereby completely remove the moisture. Here, a maintaining time is required to exclude a possibility that the moisture is formed on the surface of the document glass13again due to a temperature difference between the document read-out apparatus and its surroundings even though the temperature of the heater51reaches the target temperature of 25° C.

Table 1, the determination table, is simply one example, and, as shown in Table 2, a value of target temperature corresponding to the sensed humidity may be variously changed and applied. For example, when the sensed humidity is 35%, the target temperature is not limited to 25° C., as shown in Table 1, but may be set to 30° C., 40° C. or so forth, as shown in Table 2.

In order to ensure that the moisture is completely removed, an operation S60of rechecking the humidity of the surface of the document glass13of the CIS10after the moisture is removed through the operations S120and S130can be performed, and the operations S120and S130can be repeated when the rechecked humidity exceeds the reference humidity.

While the heater51generates heat to remove the moisture, the temperature of the CIS10may exceed the driving temperature. To solve this problem, the temperature of the CIS10can be sensed by the temperature sensor57a, at operation S71. When the temperature of the CIS10is greater than the driving temperature, the CIS10can be cooled, at operation S72.

When the CIS10is cooled down to the driving temperature, the document1maintained in the standby state can be fed to the CIS10, thereby performing the operation S50of reading out the image.

Hereinafter, a description will be made about a method of removing the moisture by sensing a moisture state of the document glass13through the room temperature sensor57c, and then determining the driving conditions of the heater51according to the sensed moisture state.

FIG. 7is a flowchart illustrating the process of removing moisture on the basis of the room temperature sensor57of the moisture removing unit50.

Referring toFIG. 7, a process of reading out an image can include the operation S30of sensing whether the document1is fed, and the operation S50of reading out the image, similarly toFIG. 6. Therefore, like numbers as toFIG. 6refer to like operations, and their detailed descriptions will be omitted.

Hereinafter, an operation S200of removing the moisture, different from the operation S100shown inFIG. 6, will be described in more detail.

The operation S200of removing the moisture from the document glass can include sensing a room temperature through the room temperature sensor57c, which can be mounted to the image read-out apparatus, at operation S210, determining the driving conditions of the heater51according to the room temperature sensed in the operation S210, at operation S220, and driving the heater51according to data determined in the operation S220and checking whether the heater51reaches a driving target temperature, at operation S230.

In the operation S220, the target temperature value to remove the moisture according to the sensed room temperature can be tabulated, and then the corresponding driving condition can be adapted to be applied.

Table 3 shows one example of tabulating the target temperature according to the room temperature to determine the driving conditions.

For example, as shown in Table 3, when the room temperature sensed by the room temperature sensor57cis 10° C., the target temperature to remove the moisture can be 65° C., and the approaching speed for the target temperature can be 1500 ms (millisecond). Further, the temperature of 65° C. can be maintained for 5 seconds, to thereby completely remove the moisture. In this manner, the reason the maintaining time is required is based on the same reason as described with reference toFIG. 6.

In the process of removing the moisture through the room temperature sensor57cas described above, the heater51is heated to increase the temperature of the CIS10in order to remove the moisture. Thus, the temperature of the CIS10can be measured by the temperature sensor57aat the operation S71, and the operation S72of cooling the CIS10can be additionally provided when the temperature of the CIS10is greater than the driving temperature.

Hereinafter, a description will be made regarding a method of removing the moisture by sensing a moisture state of the document glass13through the temperature sensor57a, and determining the driving conditions of the heater51according to the sensed moisture state.

FIG. 8is a flowchart illustrating the process of removing the moisture through the temperature sensor57aof the moisture removing unit50.

Referring toFIG. 8, a method of reading out an image can include the operation S30of sensing whether the document1is fed, and the operation S50of reading out the image, similarly toFIG. 6. Therefore, like numbers as toFIG. 6refer to like operations, and their detailed descriptions will be omitted.

Hereinafter, an operation S300of removing the moisture, different from the operation S100shown inFIG. 6, will be described in more detail.

The operation S300of removing the moisture can include sensing the surface temperature of the document glass13of the CIS10through the temperature sensor57a, at operation S310, driving the heater51until its temperature reaches a target temperature corresponding to the temperature sensed in the operation S310, at operation S320, and determining whether the temperature of the heater51reaches the target temperature to remove the moisture, at operation S330.

When the surface temperature of the document glass13reaches the target temperature to remove the moisture in the operation S320, the heater can maintain the target temperature for a predetermined amount of time, and the document glass13can maintain a constant temperature to thereby remove the moisture completely.

As described above, in the process of removing the moisture through the temperature sensor57a, the heater51is heated in order to remove the moisture, and the CIS10may exceed the driving temperature. In this case, the operation S72of cooling the CIS10can be additionally provided, when the temperature of the CIS10is measured through the temperature sensor57aat the operation S71and the measured temperature exceeds the driving temperature.

As described above, the operations of removing the moisture through various sensing units57a,57band57cmay be performed either prior to reading out the image or during the reading out of the image in periods.

As described above, the present general inventive concept provides an advantage in that a document glass is directly or indirectly heated to remove moisture formed thereon, and a document is smoothly transferred without adhering to a surface of the document glass.