JP2002281201A - Image reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce device costs, and to reduce energy required for preventing dew condensation by accurately detecting the state of dew condensation in the original reading device of an image forming device without using any special means, and performing dew drop removal control. SOLUTION: This original reader of an image forming device is provided with a gain adjusting means for outputting adjustment data obtained by operating the gain adjustment of an analog signal from a photoelectric transferring means, a reading means for reading the adjusted output of the gain adjusting means, and a means for judging whether or not any dew condensation occurs from the secular fluctuation of the read adjusted output value and for controlling a dew condensation preventing heater based on the judgment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a scanner, a digital copying machine, a digital color copying machine, a facsimile,
The present invention relates to an energy saving technology applicable to an image reading apparatus of an image forming apparatus such as a color facsimile, and more specifically, detects dew condensation in the image reading apparatus by using existing gain adjusting means, and accordingly prevents dew condensation. The present invention relates to an image reading apparatus that performs the following.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No. H11-205557 discloses an image forming apparatus which reads a dew condensation detection chart, detects dew condensation on a mirror or a lens of an optical system, and performs a dew condensation operation. Also, in JP-A-6-270264,
There is disclosed an image reading apparatus in which an existing heat source is used in an image reading apparatus to heat a mirror, an optical carriage provided with a lens, and the like, which is a dew condensation preventing object, to prevent dew condensation.

[0003]

SUMMARY OF THE INVENTION It is a first object of the present invention to perform dew condensation detection by using the function of the AGC for adjusting the gain of the white level of an analog signal output from a CCD. If cloudiness occurs due to condensation on the system mirrors and lenses, the gain adjustment is set to a high value, and this gain adjustment value is used to determine whether condensation has occurred. Cost reduction is achieved by detecting the dew condition without using a dew condensation sensor (greenhouse temperature sensor) or a dew detection chart, etc. In addition, the dew condensation prevention heater can be automatically set to minimize the cause of dirty outside air flowing into the inside of the scanner and contaminating the mirror, lens, contact glass, and the like of the optical system.

A second object of the present invention is to perform a dew condensation preventing process with high accuracy without using a high adjustment value immediately after power-on as control data.

[0005] A third object of the present invention is to make it possible to perform optimum setting depending on the installation area and setting environment of the user.

A fourth object of the present invention is to detect dew condensation with high accuracy by discriminating whether the amount of light is reduced due to dew condensation or other factors such as contamination of an optical system (mirror and lens) and deterioration of illumination means (halogen lamp). Is to be able to
A fifth object of the present invention is to perform dew condensation prevention processing with high accuracy without using a high adjustment value that appears immediately after power-on as control data.

A sixth object of the present invention is to use a condensation prevention heater originally provided for dew condensation prevention as a dew condensation release operation so that the dew condensation release operation can be performed without increasing costs. An object of the present invention is to perform a dew condensation releasing operation efficiently without increasing costs by performing lamp-on scanner free-run as the dew condensation releasing operation.

[0008]

According to a first aspect of the present invention, there is provided an optical system which illuminates an original image and guides the light image to photoelectric conversion means, and outputs adjustment data obtained by adjusting the gain of an analog signal from the photoelectric conversion means. In an image reading apparatus having an adjustment unit (AGC), a control unit (CPU), and a condensation prevention heater in the optical system, a unit for detecting a change in adjustment data, and controlling the condensation prevention heater in accordance with an output of the unit. An image reading apparatus characterized by having means.

According to a second aspect of the present invention, in the image reading apparatus of the first aspect, the adjustment data obtained by executing the gain adjustment immediately after the power is turned on and the adjustment data after the execution of the gain adjustment after a predetermined time elapses. In comparison, a means for determining whether or not the optical system is in a dew state and a means for controlling the dew condensation prevention heater in accordance with the determination result are provided.

According to a third aspect of the present invention, in the image reading apparatus according to the first or second aspect, the control setting of the dew condensation prevention heater can be changed by input setting (SP mode) from the operation display unit. An image reading apparatus characterized in that:

According to a fourth aspect of the present invention, there is provided the image reading apparatus according to any one of the first to third aspects, further comprising a non-volatile storage means for storing adjustment data after the gain adjustment has been performed,
The image reading apparatus is provided with a means for comparing the history of the adjustment data and, when the difference exceeds a predetermined value, discriminating whether or not the difference is due to a dew condensation state.

According to a fifth aspect of the present invention, in the image reading apparatus according to the fourth aspect, when the adjustment data is adjusted within a predetermined time after the power is turned on, whether the setting is fixed setting or automatic setting is determined, and the automatic setting is performed. In this case, the image reading apparatus is characterized in that it is determined whether or not to perform an abnormal process (SC call) based on a difference between the adjustment data and the adjustment data after a predetermined time has elapsed.

According to a sixth aspect of the present invention, there is provided an image reading apparatus according to any one of the first to fifth aspects, wherein a dew condensation prevention heater is turned on as a dew condensation releasing operation.

According to a seventh aspect of the present invention, in the image reading apparatus according to any one of the first to sixth aspects, the lamp ON free-run (the ON state of the supply / exhaust fan) is executed as the dew condensation releasing operation. Image reading device.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An image forming apparatus for carrying out an embodiment of the present invention will be described with reference to FIG. The original is scanned by the image reading unit 2 while irradiating the original with a light source, and reflected light from the original is reflected on three lines C.
The image is read by the CD sensor, and the image data is sent to the image processing unit 3. The image processing unit 3 sends to the image writing unit 4 image data that has been subjected to image processing such as scanner γ correction, color conversion, main scanning magnification, image separation, processing, area processing, and gradation correction processing. The image writing unit 4 modulates the driving of an LD (laser diode) according to the image data. The drum unit 8 writes a latent image on the uniformly charged rotating photosensitive drum by the laser beam from the LD, and the developing unit 1
With 0, the toner adheres and is visualized.

The image formed on the photosensitive drum is retransferred onto the transfer belt of the intermediate transfer unit of the intermediate transfer unit 9. In the case of a full-color copy, four color toners are sequentially superimposed on the intermediate transfer belt. (4 of Bk, C, M, Y
In the case of full-color copying, when the four-color image forming and transferring process of Bk, C, M, and Y is completed, transfer paper is fed from the paper feeding unit (11) in synchronization with the timing of the intermediate transfer belt. Then, the toner is transferred from the intermediate transfer belt to the transfer paper at the same time in the paper transfer section. The transfer paper to which the toner has been transferred is sent to the fixing unit 12 via the conveyance unit, and is heat-fixed by the fixing roller and the pressure roller to be discharged. Items set by the user, such as the copy mode, are input by the operation unit 5. The set operation mode such as the copy mode is sent to the system control unit 1, and the system control unit 1 performs a control process for executing the set copy mode. At this time, from the system control unit,
A control instruction is issued to units such as an image reading unit, an image processing unit, an image writing unit, and an image display unit.

The image data output from the image processing unit 3 is transferred to the DRAM 21 for storing image data by the DMA controller built in the CPU 23 via the FIFO 21 in the functional block diagram of the image display unit 7 shown in FIG.
22.

Since an image data control signal is sent to the image display unit 7 together with the image data, it is possible to capture only the effective image area. The valid image data stored in the DRAM 22 is transmitted to the VR by the CPU 23.
DMA transfer is performed to the AM 24. At this time, it is also possible for the CPU 23 to transfer an arbitrary part of the image data in the DRAM 22 and to perform processing such as enlargement, reduction, thinning, etc.

The image data transferred to the VRAM 24 is controlled by an LCDC (LCD controller) to output L data.
Displayed on the CD panel.

FIG. 3 is an explanatory diagram of the image display unit.
The image display unit may display an image on the LCD, and may also serve as a display editor for designating an editing / processing area / setting a mode on the screen. Each setting key in FIG. 3 corresponds to a keyboard portion 31 in the functional block diagram in FIG.

FIG. 4 shows an example of the operation unit. In the figure, 41 is a numeric keypad, 42 is a mode clear / preheat key, 43 is an interrupt key, 44 is an image quality adjustment key, 45
Is a program key, 46 is a print start key, 47
Clear / stop key, 48 area processing key, 49 is a brightness adjustment knob, 50 is a touch panel key arranged on an LCD (liquid crystal panel), 51 is an initial setting key,

The ten keys 41 are used to input numerical values such as the number of copies. The mode clear / preheat key 42 is used to cancel the set mode and return to the initial setting, or to set the preheating state by pressing continuously for a certain period of time or more. The interrupt key 43 is used to interrupt during copying and to copy another document. The image quality adjustment key 44 is used to adjust the image quality. The program key 45 is used to register or call a frequently used mode. The print start key 46 is a key for starting copying.
The clear / stop key 47 is used when clearing the input numerical value or when interrupting copying during copying. The area processing key 48 is used when using a mode such as area processing / editing on the image display unit (display editor).

The brightness adjustment knob 49 adjusts the brightness of the screen of the LCD panel. The touch panel key 50 is L
When a key area is set in the same range as the range of various keys displayed on the CD panel, and the touch panel detects a press within the set range, the set key is processed. The initial setting key 51 is pressed when the user can select each initial setting.

FIG. 5 shows an example of an LCD (liquid crystal display screen). As shown in FIG. 5, on the LCD screen, there are mode selection displays such as a color mode, an automatic density, a manual density, an image quality mode, an automatic paper selection, a paper tray, automatic paper scaling, a normal magnification, a sort, and a stack. There are also sub-screen selection displays such as create, color process, double-sided, and scaling. Keys having the same size as the size of each display are set on the touch panel.

FIG. 6 shows an example of screen development by pressing the scaling key on FIG. When the scaling key is pressed, the scaling setting screen is scrolled up from the bottom of the screen. On the magnification setting screen, keys for fixed magnification (magnification mode in which a magnification is set in advance) are set. For example, when the touch panel key of the 71% portion is pressed, a scaling ratio of 71% is selected. Further, on this screen, a zoom key, a dimension scaling key, and an independent scaling / enlargement continuous shooting key are set on the left side of the screen in order to select a scaling mode other than the standard scaling.

FIG. 7 shows an example of a touch panel detection circuit, and FIG. 8 shows a setting state of X1, X2, Y1, and Y2. The controller sets the detection terminal to H
In the high state, X1, X2, Y1, and Y2 are set as shown in FIG. Since the circuits of Y1 and Y2 are pulled up by resistors, when the touch panel is OFF, Y1 and Y2
Becomes + 5v, and becomes 0v when ON. Therefore, A /
Check the ON / OFF status from the output of the D converter. The controller switches to the measurement mode when detecting the ON state of the touch panel. In the X direction, X1 is +
5v and X2 become 0v, and the potential at the input position is connected to the A / D converter through Y1 to calculate the coordinates.
The coordinates in the Y direction are similarly calculated by switching the circuit. With such a detection circuit, the pressed position of the touch panel is detected.

FIG. 9 is a block diagram of the operation unit. An address signal from the CPU 53 is taken into an address latch 54, and is controlled here by a signal from the CPU 53. A part of the address signal output from the address latch 54 enters an address decoder 56, where a chip select signal for each IC is created and used for creating a memory map. The address is RO
M, RAM and other memories and LCDC are used for address designation.

On the other hand, a data bus from the CPU 53 is connected to a memory or an LCDC to perform bidirectional data communication. LCDC 55 is an address bus from CPU 53,
In addition to the data bus, an LED driver 59, a keyboard 60, an analog touch panel 61, an LCD module 62, and a ROM 63 and a RAM 64 for display data
Etc. are connected. The LCDC 55 creates display data from ROM and RAM data based on a signal from a keyboard or a signal from a touch panel, and controls display on the LCD 62. An optical fiber connector is connected to the CPU 53 to communicate with the outside.

FIGS. 10 and 11 show overall block diagrams of the image reading apparatus of the present invention. C on the scanner IPU control unit
The PU 101 executes a program stored in the ROM 102 and reads and writes data and the like in the RAM 103 to control the entire scanner / IPU unit. Further, it is connected to the system control unit 104 by serial communication, and performs an operation instructed by transmission and reception of commands and data. Further, the system control unit is connected to the operation display unit 105 by serial communication, and can set an instruction such as an operation mode according to a key input instruction from a user. CPU
Reference numeral 101 denotes an I / O 106 which is connected to a document detection sensor, an HP sensor, a pressure plate open / close sensor, a cooling fan, and the like, and performs detection and ON / OFF control. The scanner motor driver (7) is driven by a PWM output from the CPU, generates an excitation pulse sequence, and drives a pulse motor 108 for driving original scanning.

An original image is formed on a three-line CCD 111 by passing a light signal through a plurality of mirrors and lenses by the light quantity output of a halogen lamp 110 driven by a lamp regulator 109. The three-line CCD is supplied with respective drive clocks by a timing circuit 112 under the control of the scanner IPU, and outputs analog image signals of odd and even of RGB to the emitter followers 113 to 115. The signals input from the emitter followers to the analog processing circuits 116 to 118 are subjected to the subtraction method CDS in the analog processing circuit, to perform line clamping in the optical black portion of the CCD, to correct the output difference between odd and even, and to set the respective amplifier gains. Make adjustments. After the gain adjustment, they are combined by the multiplexer, and finally input to the A / D converters 119 to 121 after the DC level offset adjustment.

The analog signal input to the A / D converter is digitized and input to the shading circuit 22. In the shading circuit, the light amount of the illumination
It has a function of correcting variations in the pixel output of a CD. The image data subjected to the shading correction is input to the line-to-line correction memories 123 and 124, and the image data corresponding to the number of B, G, and B and R lines of the three-line CCD is delayed by the memory, and one or more lines of the BGR read image are read. The position is adjusted and output to the dot correction 125.

In the dot correction 125, the image data output from the line-to-line correction memories 123 and 124 is corrected for the deviation of the dots within one line of the RGB data. Scanner γ
In the correction 126, the reflectance linear data is corrected by a look-up table method. The corrected image data is passed through an automatic document color determination circuit 128, an automatic image separation circuit 129, and a delay memory 127 to an RGB filter, a color conversion process, and the like.
The process is divided into a first route input to the scaling process and the create 30 and a second route of the image data memory (R, G, B) 127. The image data memory is composed of a DRAM that can store the image data of the maximum reading area of the scanner for each RGB, and it is also possible to take in the RGB image data in one scan, and to output this image when outputting a full-color superimposed image or repeat copying. It can be handled by outputting from the memory and returning to the first route.

The automatic original color judgment circuit 128 executes ACS (chromatic / achromatic judgment) processing, and the automatic image separation circuit 129 executes image area separation (character / halftone) processing. In the ACS processing, black and gray are determined. In the image area separation processing, edge determination (determined by the continuity of white pixels and black pixels), halftone determination (determined by a repetition pattern of peak / valley peak pixels in an image), photo determination (image data outside characters and halftone dots) (If any) to determine the area of the character and print (dot) and photo areas and transmit them to the CPU. RGB filters, color conversion printer γ correction, YMCK filter, and switching of parameters and coefficients in gradation processing. Is done.

The image data is input to an RGB filter. In the RGB filter, RGB MTF correction, smoothing,
Filter coefficients for edge enhancement, through, and the like are switched and set according to the determination area. In the color conversion processing, RGB data is subjected to YMCK conversion, UCR, and UCA processing. Enlargement / reduction processing is performed on the main scan image data input to the scaling processing. The branch of the image display unit 132 is performed after this processing. It is connected to the image display unit via the I / F. Create creates and edits colors. In the create edit, italic, mirror, shadowing, hollowing out processing and the like are executed. In color processing, color conversion, designated color erasure, under color, and the like are executed.

Printer γ correction, YMCK filter 131
Then, the printer γ conversion and the filter coefficient are set based on the above determination area. In gradation processing, dither processing is executed. In video control, write timing setting, image area, white area setting, test pattern generation such as gray scale and color patch can be performed. (Laser diode) and output to LD. Each function process is connected to the CPU, and executes the setting and operation of each process according to an instruction of the system control unit according to a program stored in the ROM.

Next, the dew condensation prevention control of the present invention will be described. In FIGS. 10 and 11, reference numeral 146 is a block diagram of a condensation prevention heater control circuit. The AC input supplied to the dew condensation prevention heater 140 is turned ON / OF by the power relay 141.
F is controlled. The control of the power relay is controlled by the logic circuit 143 via the driver 142. The logic circuit is set by software processed by the CPU 101. The non-volatile RAM 103 of this CPU uses a secondary battery 145 together with a condensation prevention heater control circuit to control the main body PSU.
Is backed up so that it can be controlled even when the DC power supply is turned off. This enables power relay control when the main power supply is turned off, and the dew condensation prevention heater is turned on,
The OFF state can be arbitrarily selected.

Next, the SP mode screen of the condensation control heater control setting which can be input from the operation display unit will be described. In the present embodiment, an example in which the setting screen is provided in the SP mode has been described, but a screen that can be directly operated by the user does not matter. FIG. 12 shows a selection screen for selecting automatic setting and fixed setting for dew condensation prevention heater control. When the automatic setting is selected, the condensation prevention heater automatic setting screen shown in FIG. 13 is displayed. The automatic setting of the dew condensation prevention heater starts when the dew condensation prevention heater is OFF regardless of whether the main power supply is ON or OFF. The present invention turns on a dew condensation prevention heater when dew condensation is likely to occur due to dew detection using a gain adjustment value of AGC.
Basically, the condensation prevention heater is turned on when the main power supply is turned off. The problem here is when to return to the default of the automatic setting after switching the control after detecting the dew condensation. However, since the dew condensation time is limited only in winter or rainy season, the date of dew condensation detection and deactivation of the dew condensation prevention heater operation are shown in FIG. Can be determined. In the illustrated example, 10 days are set.

When the fixed setting is selected in FIG. 12, a fixed setting screen shown in FIG. 14 is opened. This makes it possible to freely select the control of the dew condensation prevention heater when the main power is off and when the main power is on. This can expand the response overseas and in the installation environment where the degree of greenhouse changes is abundant outside of Japan.

FIG. 15 is a flowchart showing a specific procedure for controlling the dew condensation prevention heater. In FIG. 15, the dew condensation prevention heater control is performed by first operating the operation display unit (or S
A dew condensation prevention heater control setting check (P mode) is performed (S101), and the control is divided into control of automatic setting or fixed setting by checking the SP mode setting of the operation display unit (S102). At the time of the fixed setting (S102, No), the main power is turned off as shown in the figure by the dew condensation prevention heater flags 3, 4, 5, and 6.
And heater control at the time of ON.

At the time of automatic setting (S102, Yes), it is determined whether the dew condensation detection flag is ON (S104), and if it is ON (S104, Ye)
s) It is determined whether or not the dew condensation prevention heater operation release has passed (S107). If it has passed (S107, Yes), the dew condensation prevention heater flag 1 is set (S107) and the dew detection flag is turned off.
(S108), and ends the process.

In step 104, if the condensation detection flag is not ON (S104, No), the condensation prevention heater flag 1
Is set to OFF when the main power is OFF, and OFF when the main power is ON (S106), and the process ends.

If it is determined in step 105 that the date on which the dew condensation prevention heater operation has been canceled has not passed, the process ends. Then, the dew condensation prevention heater flag is set by checking the dew condensation prevention heater operation setting release date, and the heater is controlled.

FIG. 16 is a flowchart showing the procedure of the dew condensation detection and release operation. The dew condensation detection will be described briefly. After setting the reference black level, the ADC Vr
The reading white level is set so that the dynamic range of ef can be properly set. This read white level is the gain adjustment. The gain increases as the adjustment data increases.
Therefore, dew condensation is detected by looking at the gain adjustment data value. That is, the AGC 1 after the power is turned on compares the gain adjustment data with the last final gain adjustment data, and if the difference does not exceed the predetermined value A, the second A
After the execution of GC, the operation is completed and the reading operation is enabled. When the difference is larger than the predetermined value A, the heater flag 3 at the time of the fixed setting,
At 4, 5, and 6 o'clock, an abnormal processing SC call is issued and the processing ends.
At the time of automatic setting, release condensation. The dew condensation state is released by performing the dew condensation heater ON and the lamp ON free run. After that, the AGC 2 is executed to compare the adjustment data 1 with the adjustment data 2. If there is no change, the SC call is made as an abnormality of the optical system (dirt of the optical system, deterioration of the illumination system, etc.). If there is an improvement compared with the last gain adjustment data in the previous time, but it is not enough, the lamp ON free-run is further executed to release the dew condensation. When the last gain adjustment data value becomes almost equal to the last time, the final adjustment value is backed up by a battery and saved in the nonvolatile RAM, and can be used for the next control.

The process of dew condensation detection and release operation will be described. First, AGC which is an initial setting operation of the reading operation is performed.
(Auto gain control) (S201),
As a result, the gain adjustment data 1 is saved (S20
2). Here, a difference between the gain adjustment data 1 and the last final gain adjustment data is compared with a predetermined value A (S203).
If the difference is larger than the predetermined value A (S203, Yes) and the dew condensation prevention heater flags 3, 4, 5, 6, and 7 are not set, that is, if the setting is automatic, it is determined that dew is present. To turn on the condensation heater (S205). Then, in this state, the lamp is turned on and free-run is performed (S20
6) Continue for a predetermined time (S207) and end (S20)
8). Next, the second AGC is executed (S209).
Save the second gain adjustment data (S210), where
The difference between the gain adjustment data 2 and the previous first gain adjustment data is compared with a predetermined value B (S212). If the difference does not exceed the predetermined value B (S203, No), the dew condensation detection flag is set to O.
N (S212), the difference between the gain adjustment data 2 and the last final gain adjustment data is compared with a predetermined value A (S21).
3) If the difference does not exceed the predetermined value A (S213, N
o), the dew condensation heater is turned off assuming that the dew has been eliminated (S21
4) Set the dew condensation prevention heater flag 2 and
Set to ON when F and OFF when main power is ON
(S215). Then, the second gain adjustment data is saved as the final gain adjustment data (S216), and the process ends.

In step 203, the difference between the gain adjustment data 1 and the last final gain adjustment data is compared with a predetermined value A (S203). If the difference does not exceed the predetermined value A (S202, No), dew condensation occurs. It is determined that there is no data, and after a predetermined time has elapsed (S218, Yes), the second AGC is executed (S219).
The second gain adjustment data is saved (S220), and the second gain adjustment data is saved as final gain adjustment data (S221), and the process ends.

In step 204, the dew condensation plug 3,
If 4, 5, 6 is set, that is, if the setting is fixed, an abnormal processing SC call (S217) is issued and the processing ends.

In step 211, the difference between the gain adjustment data 2 and the previous first gain adjustment data is compared with a predetermined value B (S212). If the difference exceeds the predetermined value B (S211, Yes) As described above, it is determined that there is an abnormality in the optical system (dirty of the optical system, deterioration of the illumination system, etc.), and the dew condensation heater is turned off (S222), and an abnormality processing SC call is performed (S223).

[0048]

According to the first aspect of the invention, when the AGC is performed as an initial setting operation before the image reading scan of the image reading apparatus, the AGC adjusts a white level gain of an analog signal output from the CCD. However, since dew condensation is detected using this function, the dew condensation state can be detected without using a new special dew sensor (greenhouse temperature sensor), a dew detection chart, or the like, and cost can be reduced. In addition, by controlling ON / OFF of the dew condensation prevention heater based on the above detection result, dew condensation can be performed in a non-condensation period other than a dew condensation period such as a winter office (a state in which night heating is turned off and morning heating is turned on and the room is rapidly heated) and a rainy season. Since the prevention heater can be turned off, power can be saved. Further, by setting the automatic setting, an air current is generated inside the scanner by turning on the dew condensation prevention heater when the main power is turned off. For example, if the outside air is contaminated with cigarette smoke or the like, the air flow is generated. It is possible to minimize the risk that the mirror or lens of the optical system, the contact glass, and the like that flow into the inside and become dirty will be contaminated.

According to the second aspect of the invention, by executing the gain adjusting means (AGC) immediately after the power is turned on, if the mirror or lens of the optical system is fogged by condensation, the gain adjustment value is set to a high value. After a lapse of a specific time after the power is turned on, the entire device is warmed up and the gain adjusting means (AG
When C) is executed, the gain becomes the adjustment value in the normal state at the time of gain adjustment. Therefore, the invention according to the present invention has an effect of detecting dew condensation by comparing individual adjustment data, controlling the dew condensation prevention heater based on the detection result, and reducing a problem due to dew condensation.

Effect corresponding to the third aspect: The dew condensation prevention heater is turned on when the normal power is turned off (AC power cord is connected), and is turned off when the power is turned off. In the present invention, the condensation prevention heater is automatically set (default state)
Then, regardless of whether the power is OFF or ON, the dew condensation prevention heater is OF
It becomes F. In Japan, automatic setting and automatic switching of the dew condensation prevention heater when the power is turned off only at the dew condensation occurrence time is a good result in consideration of power saving. Depending on the location of the overseas installation, the area where condensation does not occur throughout the year
De-energized state is good irrespective of FF, ON, and conversely, in areas where the difference in greenhouse degree is very large in one day or one year, the current normal setting, or the dew condensation prevention heater is always on regardless of the power OFF and ON The case where the ON state is good may extremely rarely occur, but according to the present invention, the setting of the operation display unit (SP mode setting) is performed according to the installation area of the user and the setting environment. By doing so, you can adjust to the optimal setting.

According to the fourth aspect of the present invention, the amount of light reduction due to dew condensation and the amount of light reduction due to dirt on the optical system (mirror, lens) and the illumination means (halogen lamp) can be adjusted by adjusting data of the gain adjustment means when AGC is performed. By storing it, it is possible to distinguish it, and it is possible to detect dew condensation with high accuracy.

Effect corresponding to claim 5: A after power-on
GC (gain adjustment) is necessary to perform FAX transmission and scanner image transfer to a personal computer before the fixing start-up wait time on the image forming apparatus side. However, when the dew condensation prevention heater is automatically set, a gain adjustment error due to dew condensation occurs. Although they may occur, these are not real failures. The invention according to the present invention has an effect of not performing an abnormal process (SC call) when a gain adjustment error occurs again when the AGC is executed again after a specific time has elapsed (after dew condensation has been restored due to a rise in the temperature inside the apparatus).

According to the sixth aspect of the invention, the decondensation releasing operation can be performed without increasing the cost by using the dew condensation preventing heater originally provided for the dew condensation preventing operation.

The effect corresponding to claim 7 is that by performing lamp-on scanner free-run as the dew condensation releasing operation, there is an effect that the dew condensation releasing operation can be performed efficiently without increasing the cost.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an entire image forming apparatus for carrying out an embodiment of the present invention.

FIG. 2 is a functional block diagram of an image display unit.

FIG. 3 is an explanatory diagram of an image display unit.

FIG. 4 is a diagram illustrating an example of an operation unit.

FIG. 5 shows a display unit (liquid crystal display screen).

FIG. 6 shows a development screen when a scaling key is pressed on the display unit in FIG. 5;

FIG. 7 is a diagram illustrating an example of a touch panel detection circuit.

FIG. 8 is a diagram illustrating a setting state of X1, X2, Y1, and Y2 in FIG. 7;

FIG. 9 is a block diagram of an operation unit.

FIG. 10 is a control block diagram 1 of an image reading unit provided with a dew condensation prevention heater control circuit.

FIG. 11 is a second control block diagram of the image reading unit including the dew condensation prevention heater control circuit.

FIG. 12 is an example of a display screen, showing a screen for setting dew condensation prevention heater control.

FIG. 13 is an example of a display screen, showing a screen for setting the number of operating days of a dew condensation prevention heater.

FIG. 14 is an example of a display screen, showing a fixed setting screen of the dew condensation prevention heater selected in FIG.

FIG. 15 is a process flowchart for explaining the dew condensation prevention heater control.

FIG. 16 is a processing flowchart for explaining the dew condensation detection and release operation.

[Explanation of symbols]

101: CPU, 102: ROM, 103: RAM, 1
04 ... System control unit, 105 ... Operation display unit, 106 ...
I / O, 146 ... dew condensation prevention heater circuit,

Continued on the front page F-term (reference) 2H027 DA07 DA14 DA35 DA38 DE02 DE07 DE09 EA11 EC06 EC09 EC10 EC18 EC20 ED04 EF01 EF08 EF17 EF18 EG02 EK03 EK09 GA03 GA14 GA23 GA34 GA35 GA45 GA47 GB14 GB19 HA03 HA04 JA12 JB19 JC08 A EA22 5C062 AA02 AA05 AB02 AB33 AB40 AB47 AC58 AE15 5C072 AA01 BA12 CA02 CA09 CA10 EA05 UA05

Claims (7)

[Claims] An optical system for illuminating a document image and guiding the light image to a photoelectric conversion unit, an adjustment unit for outputting adjustment data obtained by adjusting a gain of an analog signal from the photoelectric conversion unit, a control unit, and the optical system An image reading apparatus having a dew condensation prevention heater, comprising: means for detecting a change in adjustment data; and means for controlling the dew condensation prevention heater in accordance with an output of the means. 2. The image reading apparatus according to claim 1, wherein the adjustment data obtained by executing the gain adjustment immediately after the power is turned on is compared with the adjustment data after the execution of the gain adjustment after a predetermined time has elapsed. An image reading apparatus comprising: means for determining whether the system is in a dew condensation state; and means for changing control of a dew condensation prevention heater according to a result of the determination. 3. The image reading apparatus according to claim 1, wherein the control setting of the dew condensation prevention heater can be changed by input setting from an operation display unit. 4. The image reading apparatus according to claim 1, further comprising: a nonvolatile storage unit configured to store adjustment data after gain adjustment has been performed, wherein the stored adjustment data and the current adjustment data are stored. And a means for determining whether or not a dew condensation state occurs when the difference exceeds a predetermined value. 5. The image reading apparatus according to claim 4, wherein when the adjustment data is adjusted within a predetermined time after the power is turned on, whether the setting is a fixed setting or an automatic setting is determined. An image reading apparatus characterized in that it is determined whether or not to perform an abnormality process based on a difference between data and adjustment data after a predetermined time has elapsed. 6. The image reading apparatus according to claim 1, wherein a dew condensation prevention heater is turned on as a dew condensation releasing operation. 7. The image reading device according to claim 1, wherein the lamp is turned on as the dew condensation releasing operation.
An image reading apparatus for performing a free run.