JP2007295068A - Image reader and control method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image reader capable of executing reading operations, without stopping the device, even when cooling fans become faulty. <P>SOLUTION: Before starting the reading operation, the cooling fans 38a, 38b are driven and the state of them is investigated. A reading mode is selected, depending on the presence/absence of faults in the cooling fans 38a, 38b. Even if the cooling fans become faulty, the reading operation can be started. Moreover, during the reading operation, the state of the cooling fans 38a, 38b is investigated likewise, and the reading mode is changed, depending on the presence/absence of faults in the cooling fans 38a, 38b. Even if the cooling fans become faulty, the reading operation can be continued. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image reading apparatus that reads an image of a document in accordance with a reading mode determined from a plurality of reading modes, and a control method therefor.

  Conventionally, in an image reading apparatus mounted on a copying machine or the like, a one-dimensional sensor has been adopted in order to read an image with high resolution and to reduce the size of the apparatus. Image reading is performed by relatively moving the original to be read and the reading unit of the image reading apparatus, and is roughly classified into two methods: moving the original or moving the reading unit. Furthermore, a total of four types of image reading methods can be combined depending on whether the document is automatically guided to the reading surface of the image reading device or manually placed. Actually, the method of moving the document manually with the reading unit fixed is often unable to perform faithful reading, so three types of methods other than this method are currently widely used.

  First, a method (fixed reading method) in which an original is manually placed on a reading surface and an image is read by moving a reading unit will be described. The operator opens an automatic document feeder (ADF) having a pressure plate to suppress the document placed on the reading surface, places the document on the reading surface, and instructs the image reading device to start reading. Thus, the image of the entire document is read by scanning the reading unit in the sub-scanning direction orthogonal to the main scanning direction while reading the document one-dimensionally in the main scanning direction by the reading sensor. Here, the main scanning direction is a direction perpendicular to the direction in which the reading unit moves.

  Next, a method of reading an image (ADF fixed reading method) by automatically supplying a document, stopping the document once, and moving a reading unit will be described. The operator places a document on the ADF and commands reading start. As a result, the document is guided to the reading surface by the ADF. Thereafter, as in the fixed reading method, the reading sensor scans the reading unit in the sub-scanning direction orthogonal to the main scanning direction while reading the original one-dimensionally in the main scanning direction.

  Finally, a method (flow-reading method) in which an original is automatically supplied, an image is read while the original is fixed and the original is moved will be described. The operator places a document on the ADF and commands reading start. Accordingly, the reading unit moves to a predetermined position and stops, and is read one-dimensionally in the main scanning direction by the reading sensor. Along with this, the ADF moves the document in the sub-scanning direction, thereby reading the entire document image.

  Among the three types of image reading, in the case of the fixed reading method, the operator can place the document while confirming it on the reading surface, so that misalignment of the document can be reduced. Further, since the scanning unevenness of the reading unit is small with respect to the paper feed speed unevenness of the ADF, an image can be read with high accuracy. On the other hand, it takes time to read many originals continuously because the operator performs an operation of placing the originals on the reading surface.

  On the other hand, in the case of ADF fixed reading, the operator automatically puts or replaces the original on the reading surface, so when reading many originals continuously, the time is greatly reduced compared to the fixed reading method. be able to. On the other hand, the accuracy and variation of document alignment are slightly inferior to those of the fixed reading method.

  On the other hand, in the case of the flow reading method, similarly to the ADF fixed reading method, it is possible to omit the operation of placing and exchanging originals by the operator. Therefore, when many originals are read continuously, the time can be shortened. Furthermore, compared to the case where the reading unit reciprocates within the apparatus after feeding the document, the image is read simultaneously with feeding the document, so that the reading time can be further reduced as compared with the ADF fixed reading method. However, as with the ADF fixed reading method, accuracy and variation are slightly inferior with respect to document alignment. In addition, since the image is read while moving the document, the image quality of this method depends on the document conveyance capability of the ADF, which is slightly inferior to the scanning capability of the reading unit in the sub-scanning direction. Give up.

  Many actual image reading apparatuses adopt a fixed reading method as a standard, and employ one of two methods as a method for automatically supplying a document. That is, in many cases, “fixed reading method + flow reading method” or “fixed reading method + ADF fixed reading method” is adopted. Furthermore, when paper is fed by ADF, a flow reading method can be realized by changing the control. Therefore, there are image reading apparatuses having all methods. In other words, there is one having both “fixed reading method + flow reading method + ADF fixed reading method”.

  In the conventional image reading apparatus, when the document processing speed is increased, the light irradiation time per unit document tends to decrease. In order to compensate for this, the required amount of light has been secured by increasing the amount of light from the illumination lamp. Furthermore, since the document interval is narrowed in order to increase the number of reading sheets, the illumination lamp is forced to turn on continuously. Coupled with these, the temperature of the lighting lamp tended to increase significantly.

On the other hand, conventionally, a cooling fan has been installed in the image reading device, and forced convection is caused in the device to cool it (see Patent Document 1). Also, when not using a cooling fan, the temperature around the lamp is detected, and when this temperature exceeds the specified temperature, the reading mode is switched from the flow reading method to the fixed reading method to promote relative convection to the lamp section. (See Patent Document 2).
JP-A-11-194701 JP-A-6-186648

  However, in the conventional image reading apparatus, when the countermeasure for the temperature rise of the lamp is solved completely depending on the cooling fan, if the cooling fan fails, the temperature of the component exceeds the upper limit temperature. For this reason, a failure detection function is added to the cooling fan, and when the cooling fan fails, control is performed to stop the image reading apparatus so that the apparatus main body is not damaged. Therefore, the image reading apparatus does not operate until the cooling fan is restored, which is very difficult to use.

  SUMMARY An advantage of some aspects of the invention is that it provides an image reading apparatus and a control method thereof that can perform a reading operation without stopping the apparatus even when a cooling fan fails.

  In order to achieve the above object, an image reading apparatus of the present invention is an image reading apparatus that reads an image of a document in accordance with a reading mode determined from a plurality of reading modes, and is used for reading the image of the document. A cooling fan that cools a component to be cooled, a state detection unit that detects a state of the cooling fan, and a reading mode determination unit that determines a reading mode according to the detected state of the cooling fan. To do.

  An image reading apparatus control method according to the present invention is an image reading apparatus control method for reading an image of a document in accordance with a reading mode determined from a plurality of reading modes, and is a component used for reading the image of the document. A state detection step of detecting a state of a cooling fan that cools the cooling fan, and a reading mode determination step of determining a reading mode according to the detected state of the cooling fan.

  According to the image reading apparatus of the first aspect of the present invention, the state of the cooling fan is detected, and the reading mode is determined according to the detected state of the cooling fan. Therefore, even if the cooling fan fails, the reading operation can be performed without stopping the apparatus.

  According to the image reading apparatus of the second aspect, even when one cooling fan fails, the reading operation can be performed in the reading mode corresponding to the state of the other cooling fan.

  According to the image reading apparatus of the third aspect, even when the rotation capability of the cooling fan is lowered, the reading operation can be performed in the reading mode corresponding to the rotation capability.

  According to the image reading apparatus of the fourth aspect, it is possible to determine an optimum reading mode before starting the reading of the document.

  According to the image reading apparatus of the fifth aspect, even if the cooling fan breaks down during the document reading operation, the reading operation can be continued.

  According to the image reading apparatus of the sixth aspect, it is possible to determine the reading mode without waiting for the rising of the rotation of the cooling fan before starting the reading, and it is possible to speed up the image reading process.

  According to the image reading apparatus of the seventh aspect, it is possible to change the reading mode at an appropriate timing in accordance with the temperature rise of components such as a lamp.

  According to the image reading apparatus of the eighth aspect, when the number of remaining documents is small during the document reading operation, the reading operation is continued without changing the mode, so that the capability as the image reading device can be maintained high. .

  According to the image reading apparatus of the ninth aspect, when the number of originals to be read is small before the original is read, the reading operation is started in a predetermined reading mode regardless of the state of the cooling fan. Can be kept high.

  Embodiments of an image reading apparatus and a control method thereof according to the present invention will be described with reference to the drawings. The image reading apparatus of this embodiment is mounted on an image forming apparatus.

[First Embodiment]
FIG. 1 is a longitudinal sectional view showing the configuration of the image forming apparatus according to the first embodiment. The image forming apparatus includes an image reading device (reader unit) 1, a printer unit 2, a document feeding device 4, and a sheet post-processing device 5.

  The reader unit 1 converts a document into image data. The reader unit 1 includes an original document table (platen glass) 11, a scanner unit 14, a mirror unit 36, a lens 17, and an image sensor unit (CCD) 18 having a photoelectric conversion element. The scanner unit 14 is provided with a lamp 12 and a mirror 13. The mirror unit 36 is provided with mirrors 15 and 16. Further, a set of cooling fans 38 (38a, 38b) are provided inside the reader unit 1 in order to suppress the temperature rise of components such as the lamp 12.

  The printer unit 2 outputs the image data as a visible image on the sheet according to the print command. The printer unit 2 includes an exposure control unit 21, a photoreceptor 22, a developing device 23, a plurality of types of recording paper (sheet) cassettes 34 and 35, a transfer unit 26, a fixing unit 27, and a paper discharge unit 28. Further, the printer unit 2 includes a conveyance direction switching member 29, a refeed sheet stacking unit 30, and a conveyance roller 31.

  In the reader unit 1, the originals stacked on the original feeder 4 are sequentially conveyed onto the surface of the platen glass 11 one by one. The configuration and operation of the document feeder 4 will be described later. When the document is conveyed to a predetermined position on the platen glass 11, the lamp 12 in the scanner unit 14 is turned on, and the entire surface of the document is irradiated as the scanner unit 14 moves. Reflected light from the document is input to an image sensor unit (CCD) 18 via mirrors 13, 15, 16 and a lens 17. The CCD 18 performs electrical processing such as photoelectric conversion, and further performs normal digital processing. The digitally processed signal (image signal) is input to the printer unit 2.

  In the printer unit 2, the input image signal is modulated by the exposure control unit 21, and further converted into an optical signal by a laser. This optical signal irradiates the photosensitive member 22 as irradiation light. The latent image formed on the photosensitive member 22 by this irradiation light is developed by the developing unit 23.

  On the other hand, in synchronization with the leading edge of the image developed by the developing device 23, the sheet is conveyed from the sheet cassettes 34 and 35, and the image developed by the transfer unit 26 is transferred to the sheet. The transferred image is fixed on the sheet by the fixing unit 27 and then discharged from the paper discharge unit 28 to the sheet post-processing apparatus 5 side. In the sheet post-processing apparatus 5, sorting and binding are performed on the sheet output from the paper discharge unit 28 according to an operation mode designated in advance.

  When outputting sequentially read original images on both sides of a single sheet, the sheet fixed by the fixing unit 27 is once transported to the paper discharge unit 28, and then the transport direction switching member is reversed by reversing the sheet transport direction. Then, the sheet is conveyed to the sheet feeding unit 30 for refeeding through the sheet 29. When the next original is prepared, the original image is read and transferred and fixed to the sheet conveyed from the sheet stacking unit 30 as in the above process. As a result, it is possible to output two original images on the front and back surfaces of the same sheet.

  FIG. 2 is a side sectional view showing the configuration of the document feeder 4. The document feeder 4 has a document stacking tray 41 on which a bundle of documents is stacked. The document stacking tray 41 is provided with a half-moon roller 42, a separation / conveying roller 43, a separation motor (not shown), a registration roller 44, a full surface belt 45, and a belt motor (not shown). In addition, a large conveyance roller 46, a conveyance motor (not shown), a paper discharge roller 47, a flapper 48, a recycle lever 49, a paper feed sensor (not shown), a reverse sensor (not shown), and a paper discharge sensor (not shown). Z).

  In the document feeder 4, the half-moon roller 42 and the separation conveyance roller 43 are rotated by a separation motor, and the documents are separated one by one from the lowermost part of the document bundle on the stacking tray 41. The registration roller 44 and the full-surface belt 45 convey a document rotated and separated by a belt motor to an exposure position (a document path c) on the document table glass 11 through document paths a and b.

  The large conveying roller 46 is rotated by a document motor to convey the document on the document table glass 11 from the document path c to the document path e. The document conveyed to the document path e is returned to the uppermost portion of the document bundle on the stacking tray 41 by the paper discharge roller 47.

  The recycle lever 49 detects one circulation of the document. In other words, when the document feeding is started, the recycle lever 49 is placed on the top of the document bundle, the documents are fed sequentially, and the trailing end of the final document falls by its own weight when it passes through the recycling lever 49, thereby detecting one cycle of the document. Is done.

  In the case of a double-sided document, the document is once guided from the document paths a and b to the document path c. Then, the large conveying roller 46 is rotated, the flapper 48 is switched, and the leading edge of the document is guided to the document path d. Then, the document is passed through the document path b by the registration roller 44 and conveyed to the document table glass 11 by the entire belt 45 and stopped. In this way, the original is reversed along the original paths c to d to b. In addition, the number of documents can be counted by conveying the originals in the original bundle one by one through the original paths ab to c to e until it is detected by the recycle lever 49.

  FIG. 3 is a block diagram illustrating a configuration of a controller (control unit) that controls the entire image forming apparatus. The controller includes a CPU circuit unit 50, an operation unit 65, a sheet processing device control unit 66, a document feeding device control unit 56, an image reader control unit 57, an image signal control unit 53, and a printer control unit 54.

  The CPU circuit unit 50 includes a CPU 61, a ROM 62, a RAM 63, and an I / O interface 64. The CPU 61 comprehensively controls each unit by executing a control program stored in the ROM 62. The RAM 63 temporarily stores control data or is used as a work area for arithmetic processing when the CPU 61 executes a control program. In addition to the image reader control unit 57, the image signal control unit 53, and the printer control unit 54 described above, an operation unit 65, a sheet processing apparatus control unit 66, and a fan drive unit 67 are connected to the CPU circuit unit 50.

  The document feeder control unit 56 controls the document feeder 4 in accordance with an instruction from the CPU circuit unit 50. The image reader control unit 57 controls the scanner unit 14, the image sensor unit 18, and the like, and transfers an analog image signal output from the image sensor unit 18 to the image signal control unit 53.

  The image signal control unit 53 converts the analog image signal from the image sensor unit 18 into a digital signal, and then performs various processes on the digital signal. Further, the digital signal subjected to various processes is converted into a video signal and output to the printer control unit 54. The operation of the image signal control unit 54 is controlled by the CPU circuit unit 50.

  The printer control unit 54 drives the laser scanner unit (exposure control unit) 21 based on the input video signal. The operation unit 65 includes a plurality of keys for setting various functions relating to image formation, a display unit for displaying setting information, and the like. Then, a key signal corresponding to the operation of each key is output to the CPU circuit unit 50, and corresponding information is displayed on the display unit based on the signal from the CPU circuit unit 50.

  The sheet processing apparatus control unit 66 is mounted on the sheet processing apparatus 5 and exchanges information with the CPU circuit unit 50 to control the entire sheet processing apparatus.

  The cooling fan drive unit 67 drives the pair of cooling fans 38a and 38b and detects a state such as the presence or absence of a failure. FIG. 4 is a diagram showing the configuration of the cooling fan drive unit 67. The cooling fan drive unit 67 includes a motor drive unit 67 a that drives the cooling fan 38 and a failure detection unit 67 b that detects a failure of the cooling fan 38. The motor drive unit 67a is configured around transistors Q1 and Q2 that supply electric power to a fan motor on which an impeller is supported according to a drive signal from the CPU circuit unit 50.

  The failure detection unit 67b includes an FV converter that converts a signal frequency from a rotation speed sensor that detects the rotation speed of the impeller into a voltage, and a comparator that detects a failure when the voltage is equal to or lower than a threshold value. For example, a photo interrupter is used as the rotation speed sensor. When voltage is supplied to the fan motor and the rotation speed of the cooling fan 38 increases, the output voltage of the FV converter exceeds the threshold value, and therefore a signal indicating “no failure” is input from the comparator to the CPU circuit unit 50. On the other hand, if the cooling fan 38 fails and its rotation speed does not increase, the output voltage of the FV converter becomes equal to or lower than the threshold value, and a signal indicating “failure” is input to the CPU circuit unit 50 from the comparator. A DC brushless motor is used as the fan motor.

  Specifically, in the cooling fan driving unit 67, when the fan motor is rotated, the CPU circuit 50 sets the output port 0 to the H level. As a result, both the transistors Q1 and Q2 are turned on, and a voltage of 24 V is supplied to the fan motor. As a result, the fan motor rotates. When the fan motor is stopped, the CPU circuit unit 50 sets the output port 0 to the L level. As a result, both the transistors Q1 and Q2 are turned OFF, and the voltage supplied to the fan motor is 0V.

  The operation of the image reading apparatus mounted on the image forming apparatus having the above configuration will be described. The image reading apparatus according to the present embodiment has three reading modes of “fixed reading method + flow reading method + ADF fixed reading method”. FIG. 5 is a diagram showing the internal movement of the image reading apparatus in the fixed reading method. In the case of the fixed reading method, when the operator places an original P on the platen glass and instructs to start reading, the reading (CCD) sensor 18 reads in the main scanning direction. At the same time, by moving the scanner unit 14 in the sub-scanning direction, an image on the entire surface of the document is read. In this case, the document is exchanged by the operator. Since a certain amount of time is required for exchanging the original, the time during which the parts such as the lamp of the image reading apparatus are energized is shortened. Therefore, the components in the apparatus do not cause an excessive temperature rise and do not require a cooling system. In FIGS. 2A and 2B, the cooling fan is not operating.

  In the case of the flow reading method, the position of the scanner unit 14 is fixed, and the original P is conveyed in the sub-scanning direction, whereby the original image is read. In the image reading apparatus according to the present embodiment, a method called “belt-flowing reading” is employed in which areas for performing fixed reading and flow-reading are not divided. In this method, it is necessary to start reading after all the originals have entered the reading area in order to make the read image appropriate. Therefore, the reading position is distinguished by the size of the document in the sub-scanning direction. That is, there are two reading positions, “Small-flow reading” assuming that the length in the sub-scanning direction is about A4 (210 mm) and “Large-reading reading” assuming that the length is about A3 (420 mm). Broadly divided.

  FIG. 6 is a diagram showing the internal movement of the image reading apparatus in the Small flow reading method. In Small flow reading, an image on a document is read with the reading position fixed at the center in the sub-scanning direction of the image reading apparatus. In this case, since the document is continuously conveyed by the ADF, the lamp 12 is forced to be continuously lit. Therefore, since the temperature rise of the lamp 12 becomes large, the cooling of the lamp 12 is performed using the two cooling fans 38a and 38b.

  FIG. 7 is a diagram showing the internal movement of the image reading apparatus in the large flow reading method. In large-scale scanning, an image of a document is read with a reading position fixed at the most downstream side in the sub-scanning direction of the image reading apparatus. In this case, the lamp 12 is cooled by using the two cooling fans 38a and 38b for the same reason as in the Small flow reading.

  FIG. 8 is a diagram showing the internal movement of the image reading apparatus in the ADF fixed reading method. In the ADF fixed reading method, the ADF guides the document to the reading position on behalf of the operator, and moves the scanner unit 14 to read the image. Since the ADF continuously conveys the document, the operation rate of the apparatus is increased, and the temperature rise of the parts is increased accordingly. However, since the temperature rise is not as great as the flow reading, only the cooling fan 38a operates here.

  FIG. 9 is a table showing the relationship between the reading mode and the cooling fan necessary for it. This table is stored in the ROM 62 in the CPU circuit unit 50. Specifically, in the fixed reading mode, neither of the cooling fans 38a and 38b is necessary. In Small and Large flow reading modes, both cooling fans 38a, 38b are required. In the ADF fixed reading mode, the cooling fan 38a is necessary. Here, the cooling fan 38a is required, but any one of the cooling fans 38a and 38b may be required.

  Normally, the reading mode is determined by factors such as the ADF document size sensor and the degree of contamination of the platen glass during the previous document reading. However, in this embodiment, the cooling fan required for each mode is determined. Therefore, when a failure occurs in the cooling fan, the temperature rise cannot be suppressed, so the reading mode needs to be changed.

  FIG. 10 is a flowchart showing a processing procedure for determining the reading mode from the state of the cooling fan. This processing program is stored in the ROM 62, and is executed by the CPU 61 when the operator instructs to start reading the document.

  First, the two cooling fans 38 (38a, 38b) are driven (step S1). And the cooling fan 38a is investigated and it is discriminate | determined whether the cooling fan 38a has failed (step S2). If the cooling fan 38a is out of order, it cannot be changed except for the fixed reading (see FIG. 9), so the reading mode is set to the fixed reading mode (step S3). Then, this process is complete | finished.

  On the other hand, if the cooling fan 38a is normal in step S2, the cooling fan 38b is examined to determine whether or not the cooling fan 38b has failed (step S4). When the cooling fan 38b has failed, the reading mode is set to ADF fixed reading (step S5). Then, this process is complete | finished.

  On the other hand, if both the cooling fans 38a and 38b are normal in step S4, all reading modes including flow reading, ADF fixed reading, and fixed reading can be selected (step S6). Thereby, the operator selects an arbitrary reading mode via the operation unit 65. Then, this process is complete | finished.

  According to the image reading apparatus of the first embodiment, by driving the cooling fan and investigating the state thereof, it is possible to select a reading mode corresponding to the state, such as the presence or absence of a failure. Thereby, even if the cooling fan fails, the reading operation can be started. As described above, in the ADF fixed reading mode, only the cooling fan 38b may be operated.

[Second Embodiment]
In the first embodiment, when the image reading is started, the state of the cooling fan is investigated and the reading mode is determined. However, this does not correspond to the case where the cooling fan fails during the document reading operation. . The image reading apparatus according to the second embodiment can cope with a case where a cooling fan fails during a document reading operation. The determination of the reading mode at the start of reading is the same as in the first embodiment.

  Since the configuration of the image forming apparatus of the second embodiment and the image reading apparatus mounted on the image forming apparatus are substantially the same as those of the first embodiment, the description thereof is omitted by using the same reference numerals. To do. Here, processing different from that of the first embodiment is shown.

  FIG. 11 is a flowchart showing a processing procedure for changing the reading mode in accordance with the state of the cooling fan during the reading operation in the second embodiment. This processing program is stored in the ROM 62 and is repeatedly executed by the CPU 61 during a document reading operation.

  First, it is determined whether or not it is a flow-reading mode (step S11). If it is in the flow-reading mode, the state of the cooling fan 38a is examined to determine whether or not the cooling fan 38a has failed (step S12). If the cooling fan 38a has failed, there is only room for selection in the fixed reading mode, so the mode is changed to the fixed reading mode (step S13). Then, this process is complete | finished.

  On the other hand, if the cooling fan 38a is normal, it is determined whether or not the cooling fan 38b has failed (step S14). If the cooling fan 38b has failed, the mode is changed to the ADF fixed reading mode that can be operated only by the cooling fan 38a (step S15). Then, this process is complete | finished. On the other hand, if both the cooling fans 38a and 38b are normal in step S14, the flow reading mode can be continued, so the reading mode is not changed (step S16). Then, this process is complete | finished.

  On the other hand, if the flow reading mode is not set in step S11, it is determined whether or not the ADF fixed reading mode is set (step S17). If it is in the ADF fixed reading mode, the state of the cooling fan 38a is examined to determine whether or not the cooling fan 38a has failed (step S18). If the cooling fan 38a has failed, the mode is changed to the fixed reading mode (step S19). Then, this process is complete | finished. On the other hand, when the cooling fan 38a is normal, the reading mode is not changed (step S20). Then, this process is complete | finished.

  On the other hand, if it is not the ADF fixed reading mode in step S17, it is determined that the cooling fan is originally not required and the reading mode is not changed (step S21). Then, this process is complete | finished.

  As described above, according to the image reading apparatus of the second embodiment, it is possible to continue the reading operation even if the cooling fan breaks down during the document reading operation.

[Third Embodiment]
The temperature rise of components such as a lamp in the image reading apparatus does not occur immediately after the reading of the document is started, but occurs after a certain time has passed. Therefore, in the third embodiment, the reading mode is changed after a certain amount of time has elapsed since the reading was started.

  Here, the reading mode at the start of reading is determined by other factors such as the placement of the original on the ADF and the state of dust adhering to the original platen glass at the time of reading the previous original. Note that, similarly to the first embodiment, it may be determined according to the state of the cooling fan.

  The configuration of the image forming apparatus according to the third embodiment and the image reading apparatus mounted on the image forming apparatus are substantially the same as those of the first embodiment, and therefore, the same reference numerals are used and description thereof is omitted. Here, processing different from that of the second embodiment is shown.

  FIG. 12 is a flowchart showing a processing procedure for changing the reading mode from the state of the cooling fan after a predetermined time of the reading operation in the third embodiment. This processing program is stored in the ROM 62 and is repeatedly executed by the CPU 61 during a document reading operation.

  First, it is determined whether or not a predetermined time has elapsed since the reading of the document was started (step S11A). This predetermined time is registered in the ROM 62 in advance. If the predetermined time has not elapsed, this step process is repeated. On the other hand, when the predetermined time has elapsed, the process proceeds to the processing after step S11 for investigating the state of the cooling fan and changing to an appropriate reading mode. Since the reading mode changing process (steps S11 to S21) is the same as that of the second embodiment, the description thereof is omitted.

  As described above, according to the image reading apparatus of the third embodiment, the reading mode can be switched at an appropriate timing in accordance with the temperature rise of the component parts such as the lamp.

[Fourth Embodiment]
In the fourth embodiment, due to the same background as in the third embodiment, the reading mode is changed after a certain amount of document reading is performed after reading is started.

  The configuration of the image forming apparatus according to the fourth embodiment and the image reading apparatus mounted thereon are almost the same as those of the first embodiment, and a description thereof will be omitted. Here, processing different from that of the third embodiment is shown.

  FIG. 13 is a flowchart showing a processing procedure for changing the reading mode from the state of the cooling fan after a predetermined number of reading operations in the fourth embodiment. This processing program is stored in the ROM 62 and is repeatedly executed by the CPU 61 during a document reading operation.

  First, after a document reading operation is started, it is determined whether or not a predetermined number of documents have been read (step S11B). This predetermined number is registered in the ROM 62 in advance. If the predetermined number of documents has not been read, the process of step S11B is repeated. On the other hand, when a predetermined number of originals have been read, the process proceeds to step S11 and subsequent steps for examining the state of the cooling fan and changing to an appropriate reading mode. Since the reading mode changing process (steps S11 to S21) is the same as in the second and third embodiments, the description thereof is omitted.

  As described above, according to the image reading apparatus of the fourth embodiment, as in the third embodiment, the reading mode can be switched at an appropriate timing in accordance with the temperature rise of components such as a lamp.

[Fifth Embodiment]
In the first to fourth embodiments, the state of the cooling fan is investigated immediately before the reading mode is determined. The fifth embodiment shows a case where the current state of the cooling fan is stored without reference every time and is referred to at the start of the next reading. Since the configuration of the image forming apparatus of the fifth embodiment and the image reading apparatus mounted thereon are substantially the same as those of the first embodiment, description thereof will be omitted.

  FIG. 14 is a flowchart showing a processing procedure for storing the state of the cooling fan in the fifth embodiment. This processing program is stored in the ROM 62 and is repeatedly executed by the CPU 61 at predetermined time intervals.

  First, the cooling fans 38a and 38b are driven (step S31). Then, the state of the cooling fans 38a and 38b is examined to detect the presence or absence of a failure (steps S32 and S33). Then, the detection result is recorded in the RAM 63 (step S34). Then, this process is complete | finished.

  FIG. 15 is a flowchart showing a processing procedure for determining the reading mode according to the stored state of the cooling fan. This processing program is stored in the ROM 62, and is executed by the CPU 61 when the operator instructs to start reading the document.

  First, the cooling fans 38a and 38b are driven (step S41). The state (presence or absence of failure) of the cooling fans 38a and 38b recorded in the RAM 63 in step S34 is referred to (step S42). Based on the recording result, the reading mode is determined (step S43). Then, this process is complete | finished.

  The reading mode determination processing in step S43 is the same as the processing in steps S2 to S6 in the first embodiment, and thus detailed description thereof is omitted here. That is, when the cooling fan 38a has failed, the fixed reading mode is set. When the cooling fan 38a is normal and the cooling fan 38b has failed, the ADF fixed reading mode is set. When both the cooling fan 38a and the cooling fan 38b are normal, any of the flow reading mode, the ADF fixed reading mode, and the fixed reading mode can be selected.

  As described above, according to the image reading apparatus of the fifth embodiment, when reading is started, the reading mode can be determined without waiting for the rise of the rotation of the cooling fan, so that the image reading process can be speeded up. be able to.

[Sixth Embodiment]
In the second to fourth embodiments, the reading mode is changed while reading a plurality of documents. When this reading mode is changed, it takes a little time, or the number of originals read per unit time (productivity) decreases before and after the mode change. In the sixth embodiment, when the number of remaining documents is small, the ability as an image reading apparatus can be maintained high by continuing reading without changing the mode. Note that the determination of the reading mode at the start of document reading is the same as in the first embodiment.

  Since the configuration of the image forming apparatus according to the sixth embodiment and the image reading apparatus mounted on the image forming apparatus are the same as those in the first embodiment, description thereof will be omitted by using the same reference numerals. . Here, processing different from the second to fourth embodiments is shown.

  FIG. 16 is a flowchart showing a processing procedure for changing the reading mode from the state of the cooling fan when the remaining number of originals is less than a predetermined number in the sixth embodiment. This processing program is stored in the ROM 62 and is repeatedly executed by the CPU 61 during a document reading operation.

  First, it is determined whether or not the number of remaining documents is equal to or less than a predetermined number (step S11C). The predetermined number is registered in the ROM 62 in advance. Instead of registering in the ROM 62, an operator (operator) may input a predetermined number via the operation unit 65 and set it in the RAM 63. Further, the remaining number of documents is determined by subtracting one by one every time the operator inputs the total number of documents via the operation unit 65 and transports the documents. Instead of inputting the total number of originals by the operator, it may be obtained by conveying all the originals without reading them and automatically counting the number of originals before starting reading.

  If the number of remaining documents is less than the predetermined number in step S11C, the reading operation is continued in the current reading mode without changing the reading mode (step S22). Then, this process is complete | finished.

  On the other hand, if the number of remaining documents exceeds the predetermined number in step S11C, the same step processing (S11 to S21) as in the second to fourth embodiments is performed. Then, the reading mode is determined from the state of the cooling fan. Then, this process is complete | finished.

  As described above, according to the image reading apparatus of the sixth embodiment, when the remaining number of originals is small, the ability as the image reading apparatus can be maintained high by continuing the reading without changing the mode.

[Seventh Embodiment]
In the first and fifth embodiments, the document reading mode is determined from the state of the cooling fan (presence of failure) before starting document reading. As described above, there is a difference in productivity between the reading mode when there is no failure in the cooling fan and the reading mode when there is a failure. In the seventh embodiment, when the number of documents to be read is small, reading is started in a predetermined reading mode regardless of the state of the cooling fan. Thereby, the capability as an image reading apparatus can be exhibited highly.

  The configurations of the image forming apparatus according to the seventh embodiment and the image reading apparatus mounted on the image forming apparatus are the same as those in the first embodiment, and a description thereof will be omitted. Here, processing different from that of the first embodiment is shown.

  FIG. 17 is a flowchart showing a processing procedure for determining the reading mode from the state of the cooling fan when the number of originals to be read is not more than a predetermined number in the seventh embodiment. This processing program is stored in the ROM 62, and is executed by the CPU 61 when the operator instructs to start reading the document.

  First, it is determined whether or not the number of read originals is equal to or less than a predetermined number (step S1A). The predetermined number is set in the same manner as in the sixth embodiment. If the number of originals to be read is equal to or smaller than the predetermined number, the reading mode is determined without depending on the failure of the cooling fan (step S7). Then, this process is complete | finished.

  On the other hand, if the number of remaining documents exceeds the predetermined number in step S1A, the same processes of steps S1 to S6 as in the first embodiment are performed. That is, the cooling fan is driven to investigate the failure state of the cooling fan, and the reading mode is determined based on the investigation result. Then, this process is complete | finished.

  According to the image reading apparatus in the seventh embodiment, when the number of originals to be read is small, the ability as the image reading apparatus can be exhibited by starting reading regardless of the state of the cooling fan.

[Eighth Embodiment]
In the first to seventh embodiments, the two cooling fans are simply driven ON / OFF, but in the eighth embodiment, the two cooling fans are rotated in two stages, low speed and high speed, respectively. It can be driven by ability. Since the configuration of the image forming apparatus according to the eighth embodiment and the image reading apparatus mounted on the image forming apparatus are substantially the same as those of the first embodiment, the same components are denoted by the same reference numerals. Therefore, the explanation is omitted.

  FIG. 18 is a diagram showing the configuration of the cooling fan drive unit 67 in the eighth embodiment. The cooling fan drive unit 67 includes a motor drive unit 167 a that drives the cooling fan 38 and a failure detection unit 67 b that detects a failure of the cooling fan 38. The motor drive unit 167a includes a high-speed drive unit configured with the transistors Q1 and Q2 as the center and a low-speed drive unit configured with the transistors Q3 and Q4 as the center.

  In the high-speed drive unit, as in the first embodiment, the fan motor is driven at 24 V to rotate the impeller at high speed. On the other hand, in the low-speed drive unit, the fan motor is driven with a voltage one step lower than that in the high-speed drive unit to rotate the impeller at low speed.

  Specifically, when rotating the fan motor at high speed, the CPU circuit unit 50 sets the output port 0 to the H level. As a result, both the transistors Q1 and Q2 are turned on, and a voltage of 24 V is supplied to the fan motor. On the other hand, when the fan motor is rotated at a low speed, the CPU circuit unit 50 sets both the output port 0 and the output port 1 to the L level. As a result, the transistor Q4 is turned ON, and a lower voltage (for example, 11 V) is supplied to the fan motor. Further, when stopping the fan motor, the CPU circuit unit 50 sets the output port 0 to L level and sets the output port 1 to H level. As a result, the transistors Q1, Q2, and Q4 are all turned OFF, and the voltage supplied to the fan motor is 0V.

  The failure detection unit 67b includes an FV converter that converts a signal frequency from a rotation speed sensor that detects the rotation speed of the impeller into a voltage, and a comparator that detects a failure when the voltage is equal to or lower than a threshold value. For example, a photo interrupter is used as the rotation speed sensor. When voltage is supplied to the fan motor and the rotation speed of the cooling fan 38 increases, the output voltage of the FV converter exceeds the threshold value, and therefore a signal indicating “no failure” is input from the comparator to the CPU circuit unit 50. On the other hand, if the cooling fan 38 fails and its rotation speed does not increase, the output voltage of the FV converter becomes equal to or lower than the threshold value, and a signal indicating “failure” is input to the CPU circuit unit 50 from the comparator. Here, failure detection is performed in each case where voltages of 24V and 12V are supplied to the fan motor.

  FIG. 19 is a table showing the relationship between the reading mode and the fan required for it. This table is stored in the ROM 62 in the CPU circuit unit 50. In this table, the case of reading mode pattern 1 and reading mode pattern 2 is shown. The type of the reading mode pattern to be used can be arbitrarily set by the operator via the operation unit 65.

  In the reading mode pattern 1, when both the cooling fans 38a and 38b are rotating at a high speed, the large flow reading mode can be set. When one of the cooling fans 38a, 38b is rotating at a high speed and the other is rotating at a low speed, the small flow reading mode can be set. When both the cooling fans 38a and 38b are rotating at a low speed, or when one of the cooling fans 38a and 38b is rotating at a high speed and the other is malfunctioning, the ADF fixed reading mode can be set. When both of the cooling fans 38a and 38b are malfunctioning, or when one is rotating at a low speed and the other is malfunctioning, the fixed reading mode can be set.

  In the reading mode pattern 2, when both the cooling fans 38a and 38b are rotating at a high speed, the flow reading mode can be set. When one of the cooling fans 38a and 38b rotates at a high speed and the other rotates at a low speed, the ADF fixed reading mode can be set. When both of the cooling fans 38a and 38b are rotating at a low speed, or when one of the cooling fans 38a and 38b is rotating at a high speed and the other is malfunctioning, the fixed reading mode can be set. When both the cooling fans 38a and 38b are malfunctioning, or when one is rotating at a low speed and the other is malfunctioning, the reading mode cannot be set.

  FIG. 20 is a flowchart showing a processing procedure for determining the reading mode from the state of the cooling fan in the reading mode pattern 1. This processing program is stored in the ROM 62, and is executed by the CPU 61 when the operator instructs to start reading the document. Here, it is assumed that the reading mode pattern 1 is set in advance by the operator. The same applies when the reading mode pattern 2 is set.

  First, the two cooling fans 38 (38a, 38b) are driven (step S61), and the state of each cooling fan is examined (step S62). At this time, each cooling fan is driven at high-speed rotation and low-speed rotation, and the state of the cooling fan driven by the respective rotation ability is examined. As a result, when both of the cooling fans 38a and 38b can rotate at high speed, the large flow reading, the small flow reading, the ADF fixed reading, and the fixed reading mode can be selected (step S63). Then, this process is complete | finished.

  On the other hand, if one of the cooling fans 38a and 38b can rotate at a high speed and the other can rotate at a low speed as a result of the investigation in step 62, the small-flow reading, the ADF fixed reading, and the fixed reading mode can be selected (step S64). ). Then, this process is complete | finished.

  On the other hand, if both the cooling fans 38a and 38b can rotate at a low speed as a result of the investigation in step 62, the ADF fixed reading mode and the fixed reading mode can be selected (step S65). The same applies to the case where one can rotate at a high speed and the other does not move. Then, this process is complete | finished.

  On the other hand, if both the cooling fans 38a and 38b do not move, or if one of them can rotate at a low speed and the other does not move, the fixed reading mode is set (step S66). Then, this process is complete | finished.

  The operator can select a desired reading mode from the reading modes set to be selectable by the above processing, and can start a reading operation.

  21 and 22 are flowcharts showing the processing procedure for changing the reading mode in accordance with the state of the cooling fan. This processing program is stored in the ROM 62 and is repeatedly executed by the CPU 61 during a document reading operation.

  First, it is determined whether or not the current reading mode is the large flow reading mode (step S71). In the large flow reading mode, the cooling fans 38a and 38b are driven at high speed and low speed, and the respective states are examined (step S72). If both the cooling fans 38a and 38b are capable of high-speed rotation, the large-flow reading mode is continued without changing the reading mode (step S73). Then, this process is complete | finished.

  If both the cooling fans 38a and 38b can rotate at a low speed, or if one of them can rotate at a high speed and the other does not move, the mode is changed to the ADF fixed reading mode (step S74). Similarly, when one of them can rotate at a high speed and the other can rotate at a low speed, the mode is similarly changed to the ADF fixed reading mode. Then, this process is complete | finished.

  Further, when both of the cooling fans 38a and 38b do not move, or when one of them can rotate at a low speed and the other does not move, the mode is changed to the fixed reading mode (step S75). Then, this process is complete | finished.

  On the other hand, if it is not the large-flow reading mode in step S71, it is determined whether or not it is the small-flow reading mode (step S76). In the small flow reading mode, the cooling fans 38a and 38b are driven at a high speed and a low speed and the respective states are examined (step S77). When both the cooling fans 38a and 38b can rotate at high speed, the small flow reading mode is continued without changing the reading mode (step S78). Similarly, when one of them can rotate at a high speed and the other can rotate at a low speed, the small flow reading mode is continued. Then, this process is complete | finished.

  If both the cooling fans 38a and 38b can rotate at a low speed, or if one of them can rotate at a high speed and the other does not move, the mode is changed to the ADF fixed reading mode (step S79). Then, this process is complete | finished.

  If both the cooling fans 38a and 38b do not move, or if one of them can rotate at a low speed and the other does not move, the mode is changed to the fixed reading mode (step S80). Then, this process is complete | finished.

  On the other hand, if it is determined in step S76 that the mode is not the small flow reading mode, it is determined whether or not the mode is the ADF fixed reading mode (step S81). In the ADF fixed reading mode, the cooling fans 38a and 38b are driven at a high speed and a low speed, and the respective states are examined (step S82). When both the cooling fans 38a and 38b can rotate at a low speed, the ADF fixed reading mode is continued without changing the reading mode (step S83). Also, when one of the cooling fans 38a, 38b can rotate at a high speed and the other does not move, the ADF fixed reading mode is similarly continued. Also, when both of them can rotate at high speed, or when one of them can rotate at high speed and the other can rotate at low speed, the ADF fixed reading mode is similarly continued.

  If both cooling fans 38a and 38b do not move, or if one of them can rotate at a low speed and the other does not move, the mode is changed to the fixed reading mode (step S84). Then, this process is complete | finished.

  On the other hand, if it is not the ADF fixed reading mode in step S81, the fixed reading mode is continued without changing the reading mode (step S85). Then, this process is complete | finished.

  As described above, according to the image reading apparatus of the eighth embodiment, an optimum reading mode can be set according to the state of the cooling fan that can be driven with two-stage rotation capability.

  The present invention is not limited to the configuration of the above-described embodiment, and any configuration can be used as long as the functions shown in the claims or the functions of the configuration of the present embodiment can be achieved. Is also applicable.

  In each of the above-described embodiments, the case where the number of cooling fans is two has been described, but may be three or more. For example, in the case of three cooling fans, three cooling fans may be required in the flow reading mode, two cooling fans may be required in the ADF fixed reading mode, and one cooling fan may be required in the fixed reading mode. As a result, as in the first and second embodiments, it is possible to set the optimum reading mode according to the state of the cooling fan at the start of reading and during the reading operation.

  Further, in the large flow reading mode, three fans may be required, in the small flow reading mode, two cooling fans may be required, and in the ADF fixed reading mode, one cooling fan may be required. Similarly, it is possible to set the optimum reading mode according to the state of the cooling fan at the start of reading and during the reading operation.

  Instead of the two cooling fans, only one cross flow fan having a two-stage rotation capability and long in the main scanning direction may be used.

  In this case, the first (second) and second (second) rotation capacities are regarded as the same as in the case of two cooling fans, and the weak (low speed) rotation capabilities are the same as in the case of one cooling fan. Control similar to the embodiment is possible. That is, when neither strong (high speed) nor weak (low speed) rotation is possible, the fixed reading mode is set. When strong rotation is not possible and only weak rotation is possible, the ADF fixed reading mode or the fixed reading mode can be set. When both strong and weak rotations are possible, the flow reading mode, the ADF fixed reading mode, or the fixed reading mode may be set.

  Furthermore, the present invention can be applied to a case where the rotation capability can be controlled in three stages of strong (high speed), medium (medium speed), and weak (low speed). That is, when strong (high-speed) rotation is possible, set to the scanning reading mode, when medium (medium-speed) rotation is possible, set to the ADF fixed reading mode, and when weak (low-speed) rotation is possible, fixed reading The mode may be set. Alternatively, when strong rotation is possible, the large flow reading mode may be set. When medium rotation is possible, the small flow reading mode may be set. When weak rotation is possible, the ADF fixed reading mode may be set.

  The failure of the cooling fan includes not only the state where the impeller does not move at all, but also the state where the rotation speed does not reach a preset threshold value.

  Further, the present invention has been described as being applied to a reader unit of an image forming apparatus as an image reading apparatus. However, the present invention may be applied to a single scanner apparatus.

  The object of the present invention is also achieved by the following. That is, a storage medium storing software program codes for realizing the functions of the above-described embodiments is supplied to the system or apparatus. The computer (or CPU, MPU, etc.) of the system or apparatus reads out and executes the program code stored in the storage medium.

  In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments. The program code and a storage medium storing the program code constitute the present invention.

  Further, for example, a floppy (registered trademark) disk, a hard disk, a magneto-optical disk, a CD-ROM, a CD-R, or a CD-RW can be used as a storage medium for supplying the program code. Further, an optical disc such as a DVD-ROM, a DVD-RAM, a DVD-RW, a DVD + RW, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used. Alternatively, the program code may be downloaded via a network.

  Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also the following cases are included. That is, based on the instruction of the program code, an OS (operating system) running on the computer performs part or all of the actual processing. The case where the functions of the above-described embodiments are realized by such processing is also included.

  Further, the program code read from the storage medium is written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer. Thereafter, based on an instruction of the program code, a CPU or the like provided with the extension function in the extension board or the extension unit performs part or all of the actual processing. The case where the functions of the above-described embodiments are realized by such processing is also included.

1 is a longitudinal sectional view illustrating a configuration of an image forming apparatus according to a first embodiment. 3 is a side cross-sectional view showing the configuration of the document feeder 4. FIG. FIG. 2 is a block diagram illustrating a configuration of a controller (control unit) that controls the entire image forming apparatus. It is a figure which shows the structure of the cooling fan drive part. It is a figure which shows the motion inside the image reader in a fixed reading system. It is a figure which shows the motion inside the image reading apparatus in a Small flow reading system. It is a figure which shows the motion inside the image reading apparatus in a Large flow reading method. It is a figure which shows the motion inside the image reading apparatus in an ADF fixed reading system. It is a table which shows the relationship between reading mode and a cooling fan required for it. It is a flowchart which shows the process sequence which determines reading mode from the state of a cooling fan. It is a flowchart which shows the process sequence which changes reading mode according to the state of the cooling fan in reading operation in 2nd Embodiment. It is a flowchart which shows the process sequence which changes reading mode from the state of the cooling fan after the reading operation predetermined time in 3rd Embodiment. 14 is a flowchart illustrating a processing procedure for changing a reading mode from a state of a cooling fan after a predetermined number of reading operations in the fourth embodiment. It is a flowchart which shows the process sequence which memorize | stores the state of the cooling fan in 5th Embodiment. It is a flowchart which shows the process sequence which determines reading mode according to the state of the memorize | stored cooling fan. 14 is a flowchart illustrating a processing procedure for changing a reading mode from the state of a cooling fan when the remaining number of originals is a predetermined number or less in the sixth embodiment. 18 is a flowchart illustrating a processing procedure for determining a reading mode from a state of a cooling fan when the number of originals to be read is equal to or less than a predetermined number in the seventh embodiment. It is a figure which shows the structure of the cooling fan drive part 67 in 8th Embodiment. It is a table which shows the relationship between reading mode and a fan required for it. 6 is a flowchart showing a processing procedure for determining a reading mode from a state of a cooling fan in a reading mode pattern 1; It is a flowchart which shows the process sequence which changes reading mode according to the state of a cooling fan. It is a flowchart which shows the process sequence which changes reading mode according to the state of the cooling fan following FIG.

Explanation of symbols

4 Image reading device 12 Lamp 14 Scanner unit 38, 38a, 38b Cooling fan 50 CPU circuit unit 67 Fan drive unit 67a Motor drive unit 67b Failure detection unit

Claims (11)

An image reading apparatus for reading an image of a document according to a reading mode determined from a plurality of reading modes,
A cooling fan for cooling parts used for image reading of the document;
State detecting means for detecting the state of the cooling fan;
An image reading apparatus comprising: a reading mode determining unit that determines a reading mode according to the detected state of the cooling fan. A plurality of the cooling fans are provided,
The state detection means detects states of the plurality of cooling fans,
The image reading apparatus according to claim 1, wherein the reading mode determination unit determines a reading mode according to the detected states of the plurality of cooling fans. The cooling fan can be driven with a multi-stage rotational capacity,
The state detection means detects the state of the cooling fan driven by the rotational capacity of each stage,
The image reading apparatus according to claim 1, wherein the reading mode determination unit determines a reading mode according to a state of the cooling fan in each detected stage. The state detection means detects the state of the cooling fan before starting the image reading,
The image reading apparatus according to claim 1, wherein the reading mode determination unit determines a reading mode at the start of the image reading according to the detected state of the cooling fan. The state detection means detects the state of the cooling fan during the image reading operation,
The image reading apparatus according to claim 1, wherein the reading mode determination unit changes a reading mode during the image reading operation according to the detected state of the cooling fan. The state detection means includes storage means for storing the detected state of the cooling fan,
The image reading apparatus according to claim 1, wherein the reading mode determination unit determines a reading mode according to the stored state of the cooling fan.   The image reading apparatus according to claim 5, wherein the state detecting unit detects the state of the cooling fan after a predetermined time has elapsed or a predetermined number of sheets have been read after the reading operation is started.   6. The reading mode determination unit according to claim 5, wherein the reading mode determination unit does not change the reading mode regardless of a state of the cooling fan when the remaining number of documents is equal to or less than a predetermined value during the reading operation. Image reading device.   5. The reading mode determination unit according to claim 4, wherein when the number of documents is equal to or less than a predetermined value before the reading starts, the reading mode determination unit determines a predetermined reading mode regardless of the state of the cooling fan. Image reading device.   The image reading apparatus according to claim 1, wherein the state detection unit drives the cooling fan to detect the presence or absence of the failure. A control method of an image reading apparatus for reading an image of a document according to a reading mode determined from a plurality of reading modes,
A state detecting step of detecting a state of a cooling fan for cooling a component used for image reading of the original;
And a reading mode determination step of determining a reading mode according to the detected state of the cooling fan.

Images