JPH0869228A - Image forming device - Google Patents

Abstract

PURPOSE: To realize direct control to safety standard/environmental regulation value by reducing air blow amount by an air blowing amount control means when a detection signal from an ozone sensor shows to be equal to or above specified concentration. CONSTITUTION: When copying is started, the ozone sensor 110 is turned on. Whether it is ozone measuring timing or not is judged. In the case it is not the ozone measuring timing, the number of copies is counted. Whether the number of copies attains the number set by a user is confirmed. When it is not the set number, operation is restored to a previous step, and when it is the set number, the ozone sensor 110 is turned off and the operation is returned. In the case of judging that the specified number of copies are obtained, ozone concentration is detected. When the detected ozone concentration is equal to or above a specified value, the revolving speed of a fan 104 is decreased to reduce the passing air amount of a filter, thereby enhancing ozone removing efficiency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for reducing ozone generated during image formation.

[0002]

2. Description of the Related Art As a conventional technique, Japanese Patent Application Laid-Open No. 2-16756
It is well known in Japanese Patent Publication No. 8 that an ozone sensor is arranged on the upstream side of an ozone filter and the ozone emission amount is controlled by changing the area of the opening of the ozone decomposing agent storage container according to the temperature or ozone detection. Further, in Japanese Utility Model Laid-Open No. 1-75252, the copying operation is stopped when the ozone concentration does not fall below a certain value even if the rotation speed of the fan is controlled to increase the rotation speed based on the output of the ozone sensor of the process section. Techniques for releasing in-machine ozone are disclosed. Further, a technique is known in which the wind velocity on the downstream side of the ozone filter is detected, and when the wind velocity is below a predetermined value, the filter is heated and regenerated, but this technique has no concept of an ozone temperature sensor.

[0003]

[Patent Document 1] Japanese Patent Application Laid-Open No. 2-16756
In Japanese Patent No. 8, the ozone sensor is on the upstream side of the ozone filter, and stable detection control is difficult. Especially, the air flow in the machine is disturbed by the movement of the optical system and the rotation of the process section. Further, regulations on ozone emitted from equipment have become stricter year by year with the recent increase in environmental awareness, and it is necessary to detect ozone emitted from equipment to protect users. Further, in the case where a detecting means for detecting ozone is provided, the toner in the apparatus is conventionally provided because the detecting means is provided near the image forming portion.
There is a problem that stable detection is difficult because the detection means is contaminated with paper dust, silicon gas, and the like.

In actual Kaihei 1-75252, in order to prevent deterioration of the drum or the like due to strong oxidizing power of ozone, when the ozone concentration in the machine is not below a predetermined value, the copying operation is stopped and the ozone in the machine is released. It is not considered that the ozone concentration in the room where the equipment is installed rises due to the released ozone.Even if it is released through the ozone filter, the deterioration of the filter causes the ozone removal rate to decrease, and the ozone concentration gradually increases. There is a problem that the concentration value of ozone released becomes high.

Further, from the viewpoint of user protection, in order to constantly monitor the ozone concentration from the device in a stable manner, a means for determining whether or not the ozone sensor is stably detecting the ozone concentration is required. Also, when it is determined that the ozone sensor has failed, the ozone concentration released from the device becomes unknown, and it is necessary to notify the operator of the message and stop the device, but in the prior art, the method for checking the ozone sensor is clarified. Was not done.

[0006]

According to another aspect of the present invention, there is provided an image forming apparatus, which blows ozone air around an image forming process to the outside of the image forming apparatus by suction or blowing, and a blowing amount of the blowing apparatus. Control means for controlling the ozone, an ozone filter disposed in the flow path of ozone air, and an ozone filter for absorbing ozone and ozone for detecting the ozone concentration when the image forming process is continuously executed for a predetermined time after the image forming process is started. The image forming apparatus is characterized in that a sensor is disposed on the exhaust side of the ozone filter and the air flow rate is reduced by the air flow rate control means when the detection signal from the ozone sensor reaches a predetermined concentration or higher. .

In the image forming apparatus according to the second aspect, when the detection signal from the ozone sensor becomes equal to or higher than a predetermined density value, the air flow rate control means reduces the air flow rate, and the air flow rate control means controls the air flow rate. Is set, the control is performed within a range that does not exceed the lower limit, and the ozone concentration is detected every predetermined time after the image forming process is started, and the ozone concentration becomes equal to or lower than the predetermined value. The image forming apparatus according to claim 1, wherein the air flow rate control means increases the air flow rate when the air flow rate is detected.

An image forming apparatus according to a third aspect of the present invention is provided with a wind speed detecting means for detecting the wind speed of the ozone air discharged by the blowing means, and ozone is discharged according to the product of the detected ozone concentration value and the wind speed value. The image forming apparatus according to claim 1, wherein the amount of air blown is controlled so that the amount becomes equal to or less than a predetermined value.

According to a fourth aspect of the present invention, there is provided the image forming apparatus according to the first aspect.
In the image forming apparatus described above, a storage unit that stores an output signal of the ozone sensor when the image forming process is stopped, and an output value of the ozone sensor when the image forming process is operating are output values stored in the storage unit. The comparing means for comparing and the comparing means for judging that the ozone sensor is abnormal when the value compared by the comparing means is less than or equal to the predetermined value, and the lower limit of the blowing amount when the ozone sensor is judged to be abnormal based on the judging result. An image forming apparatus comprising: means for setting a value.

An image forming apparatus according to a fifth aspect of the present invention includes a humidity detecting means for detecting the humidity inside the machine, an exhaust means for exhausting ozone air inside the machine through a temperature detecting means for detecting the temperature inside the machine, and an ozone removing means. In an image forming apparatus equipped with a control means for controlling the air volume of the exhaust air and a detection means for detecting the ozone concentration of the exhausted ozone air, in order to dissipate the heat from the optical system or the heating means such as the fixing device. When the minimum air volume required for the first air volume is used and the maximum air volume required for ozone removal that compensates for changes in ozone removal characteristics in the temperature / humidity environment where the ozone filter is placed is the second air volume, the air volume control device When the detection data detects a temperature equal to or higher than a predetermined temperature, the first air volume is controlled, and when the ozone detection data detects a predetermined value or higher, the second air volume is controlled to detect the temperature detection data. A is a predetermined temperature or higher, when the ozone detecting data detects a predetermined value or more, an image forming apparatus and controls the image forming apparatus in the process of lowering the temperature inside.

[0011]

According to the image forming apparatus of the present invention, since the ozone sensor is arranged on the exhaust side of the ozone filter, ozone can be detected at the most stable position of the air flow. Even if a turbulent flow occurs in the machine due to the rotation operation of the parts, the above arrangement can eliminate the influence of the turbulent flow. Further, since the discharge temperature of the device can be directly detected, it becomes possible to directly control the safety standard / environmental regulation value. Also, since the ozone filter has a honeycomb structure and a corrugated structure, it is effective in removing toner such as toner on the sensor surface, paper dust generated when the paper passes through, and silicon oil used in the fixing section at the same time as ozone. Since these foreign substances can be removed by the ozone filter, the sensor can stably detect ozone.

Further, the ozone removal rate by the ozone filter is generally determined by the time during which the ozone air contacts the ozone filter. Therefore, by reducing the air flow rate, the time for ozone air to pass through the inside of the ozone filter becomes longer, so the ozone removal efficiency increases, and more specifically, the regulated value is set for the output corresponding to the ozone concentration obtained by the ozone sensor. If it exceeds the regulation value, the driving condition of the fan can be changed to reduce the air flow rate by a certain amount, thereby improving the ozone removal efficiency.

Further, the ozone generation amount and the ozone attenuation amount change intricately depending on the temperature rise and the history of the copying process.
For example, when the multi-copy is continuously performed, the ozone detection value discharged to the outside of the apparatus of the apparatus becomes a substantially stable value in 3 to 4 minutes. In addition, if the number of copies (1 to 2) within the predetermined range was repeated, the ozone concentration did not exceed the specified value. Changes in this value may be due to factors such as sensor responsiveness, temperature rise, ozone filter absorption characteristics, etc. In consideration of these characteristics, start the image process to perform stable detection and control. After that, a stable detection value is obtained by performing measurement for a predetermined time, for example, 5 minutes after continuous copying, and stable control is possible by the value. In addition, since a detector for ozone measurement generally has a slow response time, it is necessary to perform measurement for a predetermined time, and stable measurement is possible.

According to the image forming apparatus of the second aspect, it is possible to prevent the temperature inside the apparatus from rising and to suppress the amount of ozone exhausted within a predetermined value. Also, if the ozone concentration falls below a predetermined value, there is a risk of damage to the image forming part and temperature rise due to temperature rise, toner, paper dust, silicon gas, etc. It can be prevented. Furthermore, in order to prevent the temperature rise inside the machine and to discharge the vaporized silicon oil, it is necessary to secure the minimum exhaust air volume, but this configuration ensures the minimum exhaust volume, so it is exhausted. It becomes possible to suppress the amount of ozone to be kept within a predetermined value, store the data corresponding to the lower limit value of the blown air amount, and drive the blower device (fan) with the blown air amount up to the lower limit value.

According to the image forming apparatus of the third aspect, ozone is naturally decomposed by a predetermined rate in a predetermined time if left standing. Therefore, if the amount of ozone discharged from the image forming apparatus to the outside of the apparatus is suppressed to a predetermined amount or less, the ozone concentration in the periphery does not exceed the desired value. Therefore, the ozone concentration around the apparatus can be controlled to be equal to or lower than the predetermined value by controlling the amount of discharged ozone to be equal to or lower than the predetermined amount per unit time. That is, since the amount of ozone released is determined by the product of ozone concentration and air flow, the wind speed is controlled so that the product is below a predetermined value to protect the user.

According to the image forming apparatus of the fourth aspect, even when the sensor is abnormal, it is necessary to keep the temperature rise inside the machine below a certain value, so it is necessary to secure the lower limit air volume. On the other hand, since the ozone filter is not out of order, copying can be continued by ensuring a predetermined air flow rate. Therefore, even if the sensor is abnormal, the device can be used continuously and the operating time does not decrease.
Further, if the sensor is normal, the ozone detection amount rises above a predetermined value when the image forming process operates. However, if it is abnormal, it does not change. Therefore, the abnormality can be detected, and the amount of ozone discharged from the image forming apparatus can be appropriately controlled. When it is determined that the machine is abnormal, the operator is notified by a message that the machine is abnormal, or the machine is stopped.

According to the image forming apparatus of the fifth aspect, the ozone removal efficiency of the ozone filter changes depending on temperature and humidity. Since the air flow rate control means is controlled in consideration of this change characteristic, it is possible to accurately control the ozone concentration to a predetermined value or less. That is, the temperature and humidity inside the machine change intricately depending on the temperature rise and the history of the copying process. Therefore, the temperature and humidity are monitored and the amount of air is adjusted according to the situation to improve the ozone removal performance of the ozone filter and perform accurate and stable emission control.

[0018]

【Example】

 Example 1 An example of the present invention will be described below.

FIG. 1 is a sectional view according to the present invention, in which an optical system 2 is arranged in an upper portion of a copying machine main body 1. The optical system 2 includes a copy lamp 3 including a halogen lamp or the like.
And a plurality of mirrors 4 to 7 and a zoom lens 8. A photoconductor 21 is rotatably supported below the optical system 2. As is well known, around the photoconductor 21, a charger 22, a developing unit 23, a transfer unit 24, and a charge eliminator 2 are provided.
5 etc. are arranged. When copying, the mirror base is moved in the direction A while the surface of the photoconductor 21 is charged to a predetermined potential by the charger 22, and the document cover 26 is moved.
The original document (not shown) covered by is sequentially irradiated by the copy lamp 3 from the front end. Then, the reflected light from the document is exposed to the photoconductor 21 via the optical system 2,
An electrostatic latent image is formed on the photoconductor 21. Further, when copying is performed using the automatic document feeder 27 arranged above the copying machine main body 1, the document is conveyed by the drums 29a and 29b in the document conveying path 28 of the automatic document feeder 27. The copy lamp 3 sequentially irradiates the document from the leading end through slits (not shown) provided at two positions of the document transport path 28, and the reflected light from the document is exposed to the photoconductor 21 in the same manner as described above. When an electrostatic latent image is formed on the photoconductor 21, the electrostatic latent image is subsequently developed with toner supplied from the developing unit 23 to form a toner image. After that, a sheet (not shown) is fed from the sheet feeding unit 30 including a plurality of sheet feeding cassettes, etc.
The sheet is sent to the photoconductor 21 at a predetermined timing after being temporarily stopped by the registration roller 31 as needed. Then, the toner image is transferred by the transfer device 24 onto the supplied paper. After that, the paper is peeled off from the photoconductor 21, and is conveyed to the fixing unit 33 by the conveyance device 32, where the above-mentioned toner image is fixed on the paper.
Is discharged to. On the other hand, in the case of synthetic copying or double-sided copying, the sheet discharged from the fixing unit 33 is sent to the sheet conveying path 35, and in the case of synthetic copying, it is discharged to the intermediate tray 36 as it is. After being turned upside down by the turnover unit 37, the sheet is discharged to the intermediate tray 36. If a predetermined number of sheets are stored in the intermediate tray 36,
The sheets on the intermediate tray 36 are sequentially fed from the uppermost one by the sheet feeding roller 38 and sent to the photoconductor 21 for subsequent copying.

FIG. 2 shows a schematic circuit block diagram of the present invention, and FIG. 3 shows a block diagram of the peripheral portion of the filter. First, the CPU consists of two sets, a master CPU 40 and a slave CPU 41,
The slave CPU 41 controls the operation circuit 44. A display section circuit 45 and an operation section circuit 59 are connected to the operation circuit 44 to control the display of the drawings and the operation key input. The master CPU 40 controls other than the operation section of the main body. For example, the heater lamp lighting circuit 46, the copy lamp lighting circuit 47, the process control circuit 48, the motor drive circuit 49, the clogging detection circuit 50, the ozone sensor circuit 110, and the temperature. Sensor circuit 112, humidity sensor circuit 1
15 etc. are connected. It is the ozone sensor circuit 110 and the ozone sensor 111 that detect the ozone concentration. A motor drive signal is sent from the master CPU 40 to the motor drive circuit, and when the fan 104 rotates, the air passing through the filter hits the ozone sensor 111 and detects the ozone concentration. The sensor output corresponding to the detected ozone concentration is sent to the master CPU 40 via the ozone sensor output 110. The type of ozone sensor (detector) is one that continuously changes the sensor output in response to continuously changing ozone concentration, or "0" that indicates whether or not the ozone concentration value is above a certain threshold value. There are some which perform "1" judgment.
The air containing ozone first passes through the dustproof filter 101 to remove dust, and then passes through the ozone filter 102 to remove ozone. The air further hits the ozone sensor 111, and the sensor output corresponding to the ozone concentration is input to the master CPU 40 via the ozone sensor circuit 110. In this embodiment, the air is the dustproof filter 10
1 and the ozone filter 102 are passed, but the dustproof filter 101 may be omitted. However, the ozone sensor 11
As for the stains (toner, paper dust, silicon gas, etc.) on No. 1, there is less dust filter 101. In addition, the rectifying action is increased. An ozone sensor module “AETU-2” manufactured by EBARA CORPORATION is used as a detection sensor for performing one-point control of whether or not the ozone concentration is equal to or higher than a predetermined value.

Next, a simple principle of this sensor will be described. As shown in FIG. 6, the sensor structure has a thin-film heater of platinum on one side of an alumina substrate and a thin-film electrode of platinum on the other side, and a semiconductor thin film formed on the electrode. The resistance value is greatly increased by the decomposition and absorption of. By measuring this change in resistance value at a constant current, it is detected as a voltage change and detected.

FIG. 4 shows a block diagram of the ozone sensor circuit 110. The output from the sensor is input to the comparator 116 and the alarm setting trimmer 117 on the other side determines an alarm set value (the sensor outputs when the ozone concentration exceeds a certain level). The compared result is converted into a logic level via the output circuit 118 and sent to the input port of the master CPU 40.

FIG. 5 shows the relationship between the output waveform of the ozone sensor and the ozone concentration. When the ozone concentration becomes higher than the alarm set value, the output of the comparator 116 turns ON and becomes “H”.
It becomes a level. At this time, the master CPU 40 makes "H",
By detecting "L", it can be determined whether or not the ozone concentration has exceeded a predetermined value. Further, a sensor (detector) that continuously changes its output in response to a continuously changing ozone concentration may be input to the analog input port of the master CPU 40. Fig. 7 shows the block diagram at that time.
Shown in

FIGS. 8A, 8B and 8C show the rectifying effect of an ozone filter and a dustproof filter. Here, a typical 80 mm × 80 mm axial fan and an ozone filter t15 are used. The wind velocity was measured at 9 points on the cross section at the end of the air passage 103. Fan only, fan + ozone filter Fan + ozone filter + dustproof filter 3
The measurement results of the types are shown in FIG. The fluctuation of wind speed (ripple) decreases in the order of fan only → fan + ozone filter → fan + ozone filter + dustproof filter. As described above, the ozone filter and the dustproof filter have an air rectifying function, and by providing an ozone sensor on the exhaust side of the ozone filter, turbulent flow is minimized and stable measurement can be performed.

FIG. 9 (A) shows the correlation between the discharge concentration obtained by the experimental value and the concentration in the room (closed). The room has the shape specified for UL standard ozone measurement (Fig. 9 (B)).
An ozone source was installed in the center of the room, and the average value of ozone from the start of measurement to 2 hours was compared with the concentration of ozone discharged from the source. As a result, it was found that there was some variation in the data, but they were roughly proportional (however, the exhaust air velocity of ozone air was constant). For example, in order to set the ozone concentration for 2 hours to 0.05 ppm by the UL standard method, the ozone emission concentration may be set to 0.093 ppm (see FIG. 9A).
From this, if the alarm set value in the ozone sensor 110 is 0.093 ppm, 0.093 pp
By making the discharge concentration of m or less, the concentration of the room in 2 hours can be made 0.05 ppm or less.

Next, the air flow rate and the ozone removal capacity of the ozone filter will be described. Currently, there are activated carbon and catalytic type as the material of the ozone filter, and at present, the catalytic type with relatively high removal performance is predominant. In the case of the catalytic type, it does not apparently react, but as the number of copies increases, the ozone removal performance deteriorates due to the influence of NOx. The ozone removal rate is expressed as follows.

(Concentration before passing ozone filter-concentration after passing ozone filter) / concentration before passing ozone filter) × 10
0 [%] Furthermore, the ozone removal rate of the ozone filter depends on the amount of air passing through the ozone filter (however, the dependence on ozone concentration can be ignored up to several ppm).

FIG. 10 shows the relationship between the air flow rate and the ozone removal rate. Here, SV is expressed as follows. SV (space wind speed) = passing wind speed [m / h] / ozone filter thickness [m]. The SV characteristic differs depending on the filter type and the number of cells. It is known that the ozone removal performance of an ozone filter depends on the passing wind speed if the filter volume (thickness x cross-sectional area) is constant. Summarizing the above, as the number of copies increases and the ozone filter deteriorates as shown in FIG. 11, SV
Since the relationship of the ozone removal rate changes as shown in FIG. 12, if the one used in the SV at the initial point A is used in the SV at the point B as shown in FIG. 12, the ozone removal rate is kept constant. Because of the dripping, the ozone concentration is not deteriorated due to deterioration of the ozone filter. Therefore, the ozone concentration is monitored, and the air flow rate is changed when the ozone concentration exceeds a predetermined value.

The amount of ozone and the amount of ozone generated in the device and the concentration of ozone discharged through the ozone filter change intricately depending on the temperature rise inside the machine and the history of the copying process. The concentration before the ozone filter and the concentration after passing the ozone filter in the ozone discharge part of the device were measured during continuous copying.
Is. As can be seen from this graph, the ozone concentrations of both are stable after a predetermined time (T in the figure) after the start of copying (about several minutes). In this way, stable ozone concentration can be obtained and stable control can be performed by measuring after a predetermined time after starting the image forming process. As shown in FIG. 14, when one copy is made instead of continuous copy, the ozone concentration is initially increased, but when the copying is stopped, no ozone is generated and the ozone concentration at the discharge portion is lowered. For this reason, it is difficult to perform stable control because the ozone concentration is not stable immediately after the copying of a small number of sheets or the start of copying. Further, since an ozone sensor for measuring ozone generally has a slow response time, there is a great merit of measuring after a predetermined time. The 90% response of the ozone sensor module "AETU-2" described above requires 2 minutes.

The operation of this embodiment is as follows. 27 When copying starts in S1, S2
To turn on the ozone sensor. Next, in S3, it is judged whether or not it is the ozone measurement timing. If not, the copy count is made in S8. If it is not confirmed in S9 whether or not the number of copies set by the user is reached, the process returns to S3, and if not, the ozone sensor is turned off in S10 and the process returns. If it is determined in S3 that the predetermined number of copies have been made, the ozone concentration is detected in S4.
If the ozone concentration is equal to or higher than the predetermined value, the rotation speed of the fan is reduced in S6 to reduce the amount of air passing through the filter and increase the ozone removal efficiency. Then, the copy count is cleared in S7, and the execution shifts to S9. In this embodiment, the density detection is performed every predetermined number of sheets, but this may be performed every predetermined time. Further, although the fan air volume is lowered by the sensor output, the method of lowering the fan air volume may be repeated so that the air flow rate may be detected or changed so that the air density falls below a predetermined concentration. Further, in an ozone sensor capable of continuously detecting the ozone concentration, when the ozone concentration becomes equal to or higher than a predetermined value, the increase amount of the blown air amount may be obtained and controlled from the increased amount.

(Embodiment 2) Another embodiment of the present invention will be described below.

The purpose of discharging air from the inside of the machine is to prevent temperature rise and to remove and discharge silicon gas / toner / paper dust, in addition to removing and discharging ozone. Therefore, there is a limit to how much the air flow can be reduced according to the ozone concentration. Therefore, in this embodiment, a lower limit value is provided to increase the air flow rate when the ozone concentration becomes equal to or lower than a predetermined value.

An embodiment thereof is shown in FIGS.
In this example, three types are used: a standard air volume, several levels of reduced air volume, and several levels of rising air volume. First, copying is started, the ozone concentration gradually rises, and when the alarm value is reached, the air flow rate is gradually reduced (when the ozone concentration does not decrease, the air flow rate lower limit value is set). Next, when copying is completed and the ozone concentration becomes lower than the alarm value, the air flow rate is increased stepwise. And keep it for a certain time. After that, the air flow rate is reduced to the reference value and the air volume is held.

The operation will be described with reference to FIGS. 30 and 31. When the ozone sensor and the fan are turned on in S31, S3 is performed.
In step 2, it is confirmed whether or not copying is currently performed for a predetermined time from the previous measurement. If yes, the ozone concentration is detected in step S33. At this time, if the ozone is equal to or larger than the predetermined value, the air flow rate of the fan is reduced in S35 to improve the ozone removal rate of the filter. If it is less than the predetermined value, the fan air volume is increased to prevent the temperature rise (S36). After that, the timer count is cleared (S37), and the set number of copies is performed (S3).
9), the sensor fan is turned off in S40 and the process returns.

In FIG. 31, first, the ozone sensor and the fan are turned on, and it is determined in S42 whether or not a predetermined number of sheets have been copied. If it is copying, the ozone concentration is detected in S43, and it is determined in S44 whether the ozone concentration is equal to or higher than the regulation value. If it is above the regulation value, the fan air volume is calculated from the SV-removal rate characteristic (S45), and it is checked in S46 whether the air volume is below the lower limit value. If it is less than the lower limit value, the air volume is set to the lower limit value in S48, and if it is not less than the lower limit value, the air volume is set in S47. The copy count is cleared in S49, and it is continued until the number of copies set by the user (S5
1) When finished, turn off the ozone sensor and fan (S
52).

(Embodiment 3) Another embodiment of the present invention will be described.

In the regulation of various ozone, the ozone concentration in the vicinity of the operator position is measured when the copying machine is operated in a predetermined room. Therefore, the ozone concentration directly discharged does not become a problem but is discharged. The amount of ozone generated is an issue. The amount of ozone released is the ozone concentration ([ppm], [mg /
m ³ ]) and the amount of air released. Therefore, the present embodiment is characterized in that the product is obtained from the values of the wind speed detecting means and the ozone concentration detecting means, and the amount of air blown is varied so that the amount of ozone discharged becomes less than a predetermined value. Figure 25
(A) (B) (C) shows the relationship between ozone concentration, air volume, and emission volume. First, when the copy starts at T ₀ , the ozone concentration rises and the air volume remains the standard. When T = T ₆ and ozone concentration × air volume (air velocity) reaches the regulation value, the air volume is further reduced. As a result, the ozone concentration is rising, but the amount of ozone emission is partly reduced and then increased again. Further, when T = T ₇ , the ozone emission amount exceeds the regulation value again, so the air flow rate is further reduced. As a result, the amount of ozone emission is reduced again.
By repeating this, even if the ozone concentration rises, the ozone emission amount can be kept below the regulation value, and it is possible to minimize the filling of the room with ozone. Next, an example of an implementation circuit will be described for the air blower and the air flow rate control circuit that are related throughout. Here, an example of a circuit using pulse width control (PWM) will be described. In addition to this, there are many conceivable methods such as a method of controlling with energization voltage and power, a method of providing a shutter in a blower, but any method is acceptable.

In FIG. 26, first, a waveform of a certain pulse width is output from the master CPU 40 and the transistor 120 is turned on accordingly. And the fan motor 104 driving transistor 1 connected in Darlington with the pulse width
21 is turned on to rotate the fan motor 104. By increasing / decreasing the output pulse width from the master CPU 40, the power supplied to the fan motor changes and the rotation speed of the fan changes. The amount of air blown by the fan motor changes correspondingly. In this embodiment, the pulse width to the fan motor is changed according to the output of the ozone sensor, the output of the temperature sensor, and the output of the humidity sensor to change the air flow rate.

The operation of this embodiment will be described below with reference to FIG.
In step S82, the ozone sensor, the wind speed sensor and the fan are turned on, and the ozone and the wind speed are detected in steps S83 and S84. In S85, it is determined whether or not the product of ozone concentration and wind speed is less than or equal to a predetermined value, and if not, the air volume of the fan is reduced (S86). If this product is repeated below the predetermined value, the air volume at that time is fixed in S87, and the ozone sensor, wind speed sensor, and fan are turned on in S88.
FF. As a method of reducing the air volume, a method of performing with pulse width (PWM control), a method of changing the power supply voltage, a method of attaching a shutter to the duct portion and blocking the flow path can be considered.

(Embodiment 4) Another embodiment of the present invention will be described below.

As described above as a drawback of the prior art, the copying operation is possible so that the failure of the ozone sensor is detected, and whether the apparatus is stopped or a message is displayed to the operator does not reduce the operating time of the apparatus. Moreover, it is necessary to reduce the air flow so that the ozone emission becomes low. However, it is necessary to keep the temperature rise inside the machine below a certain value, and to secure the lower limit air volume corresponding to it. By ensuring the lower limit air volume, the copying operation can be continued. In this embodiment, the difference between the detected values when the process is ON and when the process is OFF is taken, and whether the sensor is abnormal or not is checked based on whether the difference is a predetermined value or more. As another method, the value may be determined only when OFF. Further, in the case of the ozone sensor of 0.1 judgment, the judgment may be made by changing the rotation speed of the fan so that it becomes 0 when OFF and 1 when ON.

The operation of this embodiment will be described below with reference to FIG.
In S8, the ozone sensor is first turned on in S12 and the image forming process is stopped in S13. As a result, no ozone is newly generated from the device, so the ozone concentration for comparison is first detected (S14). Then, the detected value is stored in S15, the image forming process is turned ON in S16 to generate ozone from the device, and the ozone concentration is detected in S17. Similarly, when the detection value is stored in S18, the difference between the ozone detection values of the two is obtained and compared with a predetermined value (M) in S19. If the difference is smaller than the predetermined value, it is determined that the ozone meter is normal and the ozone sensor is turned off in S20. If the difference is smaller than the predetermined value, it is determined that there is a trouble with the ozone sensor and S
At 21, the trouble is displayed and the machine is stopped. In this case O
Since the difference at the time of FF ON is taken, the difference can be taken even when there is another ozone generation source or the amount of residual ozone in the room is originally large, and the reliability of trouble detection of the ozone sensor is improved.

Since S23 to S28 of FIG. 29 are the same as those of FIG. 28, the description thereof will be omitted. Process O in S29
It is determined whether the difference between the detected values at N and OFF is larger than a predetermined value (M). If the difference is smaller than the predetermined value, it is determined that there is a sensor trouble and the fan air flow rate is set to the minimum required air flow rate such as temperature rise and toner. If the difference is equal to or larger than the predetermined value, it is determined to be normal and the process returns.

(Embodiment 5) Another embodiment of the present invention will be described below.

When the minimum air volume required for heat dissipation of the optical system and the fixing device is the first air volume and the maximum air volume required for ozone removal is the second air volume, the temperature inside the machine rises and becomes higher than the predetermined temperature by the temperature detecting means inside the machine. It is necessary to set the first air volume for the safety of equipment and users. However, if the air volume is increased to prevent the temperature rise, the ozone filter removal performance will decrease. Therefore, when ozone detection exceeds a predetermined value, the second air volume is reduced to reduce ozone. However, when the ozone concentration is high and the temperature is high, the air volume must be reduced from the viewpoint of ozone, while when the temperature is high, the air volume must be increased, making it difficult to reduce both. Therefore, when the temperature and the ozone are both high, depending on the image forming conditions, a copying process for lowering both of them is performed (a wider copying interval or a copying stop time is provided) to solve the problem.
In addition, since it is not necessary to stop the device itself, it is possible to prevent a decrease in operating time.

16 and 17 (A) (B) (C) (D)
The graph for explaining an Example is shown in FIG. Usually, the first air volume of the minimum air volume that keeps the temperature rise below a predetermined value when the equipment is fully loaded,
Similarly, the second air volume having the maximum air volume at which the ozone concentration is equal to or lower than the predetermined value often has no contact point as shown in FIG. Even in such a case, in this embodiment, it is possible to always prevent the temperature from rising and to keep the exhaust ozone amount within a predetermined value.

First, an example of the temperature sensor circuit will be described with reference to FIG. Various types of temperature sensors have been put into practical use, but this time, the one using a thermistor will be described. First, the resistance value of TH changes with temperature. When the resistance value changes, the voltage division ratio of R1, R2 and TH changes and the input voltage to AMP1 changes. The impedance is converted by the AMP1 and the voltage is input to the analog voltage input port of the master CPU 40. The minimum measurement width is determined by the TH resistance variation width and the analog port resolution, and sensor detection according to temperature becomes possible.

Next, an actual schematic operation will be described. In FIG. 17, first, when copying is started at T = T ₀ , the in-machine temperature and the ozone concentration increase as the number of copies increases. If the ozone concentration exceeds the regulation value _first (T = T ₁ ),
Change the amount of electricity to the motor to gradually reduce the air flow. When T = T ₂ and the ozone concentration falls below the regulation value, the air volume is set to the reference air volume (the air volume may be increased stepwise here). After that, when the temperature inside the machine reaches the regulation value at T = T ₃ , the air volume is gradually increased in order to reduce the increase in the temperature inside the machine. It suffices to prevent the rise of the internal temperature and ozone by this, but when the internal temperature and the ozone concentration exceed the regulation values, the image forming apparatus is controlled by the process of lowering the internal temperature. This time, increase the copy interval (reduce the number of copies per unit time) to prevent temperature rise. In this example, the case where ozone exceeds the regulation value is shown first, but the opposite case is also the same, and the description thereof is omitted. Further, when the temperature and ozone are both high, the copy rate is changed to set the air volume to the standard state, but the air volume may be either the first air volume or the second air volume.

Next, the operation of this embodiment will be described below.
In FIG. 32, first, the fan, the ozone sensor, and the temperature sensor are turned on in S53, and the in-machine temperature and ozone concentration are detected in S54 and S55. Next, in S56, it is confirmed whether both the temperature and the ozone exceed the regulated values. If both exceed the regulated values, the copying process is changed to lower both the ozone and the temperature. If both are not over, first check in S57 whether the temperature is over, and if it is over, the necessary minimum air volume is set (S58, S59). Similarly, if the temperature is not over, then the ozone concentration exceeds the regulation value. It is confirmed whether or not (S60). If it exceeds, ozone is removed by setting the maximum air volume required for ozone removal (S61). When neither the temperature nor the ozone is over, the air volume is left as it is and the process returns.

(Embodiment 6) Another embodiment of the present invention will be described below.

Among the ozone filters, the catalyst material (M
For those using (n, Fe, Ni), the ozone decomposition performance decreases as the humidity increases. Therefore, it is expected that ozone emissions at high humidity will increase simply by setting the air volume. Therefore, the present invention aims to accurately control the ozone concentration by providing a humidity sensor. Further, by providing the humidity detecting means between the heat generating means and the ozone filter, it is possible to detect the humidity close to the humidity of the ozone air passing through the ozone filter, and the humidity in the vicinity of the ozone filter can be considered as the humidity of the ozone air. In addition, it is possible to compensate for the deterioration of ozone filter ozone removal performance due to changes in humidity.

FIG. 19 shows the relationship between the relative humidity of the ozone filter and the ozone removal rate. In a general catalytic ozone filter, the ozone removal rate (ozone removal performance) decreases as the relative humidity increases. FIG. 20 shows the SV-removal rate relationship described above. In order to obtain the set removal rate in the reference state, the air volume calculated from SV when the humidity shifts from p to r may be changed from the air volume 1 to the air volume 3.

Next, a specific example of humidity measurement by the humidity sensor of the embodiment will be described in detail. The humidity sensor is a pair of comb-shaped electrodes formed on an alumina substrate, screen-printed with a paste of complex oxide powder material, dried, and sintered to form a moisture-sensitive film with a ceramic thickness. There is. The moisture sensitive film forming material is a composite oxide consisting of lithium niobate, lead oxide, and manganese chromate as the main material, and additives for stabilizing the characteristics are added. The fired moisture-sensitive film is a porous sintered body having a pore size distribution of 1 μm or less necessary for adsorbing and desorbing water, and a porosity (volume ratio of pores) of about 15%. When the humidity of the atmosphere changes, water proportional to the relative humidity adsorbs and desorbs into the pores, and the electrolytic mass in the pores increases and decreases, causing the electrical conductivity to change. As a result, the resistance value also changes according to the relative humidity, so that the control described above can be performed by inputting the sensor output voltage to the analog port of the CPU.

FIG. 21 shows the structure of the humidity sensor, FIG. 22 shows the sensor output voltage characteristic, and FIG. 23 shows the relationship between the relative humidity and the set air volume.
Shown in In the humidity detection mode, the sensor output of the humidity sensor 113 at that time is read from the analog port. If the humidity in the standard state is p% and the value measured this time is r%, one of the input current, the input voltage, and the input power of the fan 104 is changed so that the air volume of 1 is changed to the air volume of 3.

The operation of this embodiment will be described below with reference to FIG.
First, in step S63, an ozone sensor, a humidity sensor,
The fan is turned on and it is determined in S64 whether or not a predetermined number of copies have been made. If not, only copy count is performed in S71, and if copying is performed, ozone and humidity are detected in S65 and S66. If ozone has a predetermined concentration or more, the optimum air volume is set based on the humidity information (S67, S6).
8). After that, the copy count is cleared in S69,
Finally, in S70, it is determined whether or not the number of sheets set by the user has been copied, and in S72, the ozone sensor, the humidity sensor, and the fan are QFF'd.

(Embodiment 7) Another embodiment of the present invention will be described below.

The ozone removal rate of the ozone filter greatly changes depending on the ambient humidity. This is shown in FIG. 24 (a).
(B) and (c). For example, in order to obtain the set removal rate at t = 30 ° C., it is necessary to reduce the air volume from 2 to 3 at t = 10 ° C. Since the ozone removal performance (ozone removal rate) changes depending on the temperature and humidity at which the ozone filter is placed, in order to maintain the initial ozone removal rate as it is in that environment, the correction method according to [claim 9] You can combine the methods. For example, if air temperature is changed by 10% and air humidity is decreased by 5%, 0.9 × 0.95
If the air flow rate is 0.855 times, it is considered that the ozone removal rate change in both can be corrected.

The operation of this embodiment will be described below with reference to FIG.
In S4, first, in S73, a fan, an ozone sensor, and a temperature sensor. The humidity sensor is turned on and the in-machine temperature and ozone concentration are detected in S74. Next, in S75, it is confirmed whether both the temperature and the ozone exceed the regulated values. If both exceed the regulated values, the copying process is changed (S76), and both the ozone and the temperature are lowered. If both are not over, first check in S77 if the temperature is over, and if over, set the required minimum air volume (S78). If the temperature is not over, the ozone concentration exceeds the regulation value this time. It is confirmed whether or not (S79). If it is over, ozone is removed by setting the maximum air volume required for ozone removal (S80). When neither the temperature nor the ozone is over, the air volume is left as it is and the process returns.

[0059]

According to the image forming apparatus of the first aspect,
Since the ozone sensor is located on the exhaust side of the ozone filter, ozone air can be detected at the most stable air flow, so even if turbulence occurs inside the machine due to movement of the optical system or rotation of the process part. With the above arrangement, the influence of turbulence can be eliminated. Further, since the emission concentration of the device can be directly detected, it becomes possible to directly control the safety standard / environmental regulation value. Also, since the ozone filter has a honeycomb structure and a corrugated structure, it is effective in removing toner such as toner on the sensor surface, paper dust generated when the paper passes through, and silicon oil used in the fixing section at the same time as ozone. Since these foreign substances can be removed by the ozone filter, the sensor can stably detect ozone. Therefore, the change with time is small, and the effect is further enhanced by disposing the dustproof filter on the upstream side of the ozone filter.

Further, the removal rate by the ozone filter is
Generally, it is determined by the time when ozone air contacts the ozone filter. Therefore, by reducing the amount of air blown, the time for ozone air to pass through the inside of the ozone filter becomes longer, so the ozone removal efficiency increases, and specifically, the regulated value is set for the output corresponding to the ozone concentration obtained by the ozone sensor. If it exceeds the regulation value, the driving condition of the fan can be changed to reduce the air flow rate by a certain amount, thereby improving the ozone removal efficiency.

Further, the ozone generation amount and the ozone attenuation amount change intricately depending on the temperature rise and the history of the copying process.
For example, when the multi-copy is continuously performed, the ozone detection value discharged to the outside of the apparatus of the apparatus becomes a substantially stable value in 3 to 4 minutes. Further, if the number of copies (1 to 2) within a predetermined range was repeated, the ozone concentration did not exceed the regulation value. Changes in this value may be due to factors such as sensor responsiveness, temperature rise, ozone filter absorption characteristics, etc., but in order to perform stable detection and control in consideration of these characteristics, the image forming process must be performed. After the start, a stable detection value is obtained by performing measurement for a predetermined time, for example, 5 minutes after continuous copying, and stable control can be performed by the value. In addition, since the detector for ozone measurement generally has a slow response time, it is necessary to perform measurement for a predetermined time, and stable measurement is possible.

According to the image forming apparatus of the second aspect, it is possible to prevent the temperature inside the apparatus from rising and to suppress the amount of ozone exhausted within a predetermined value. Also, if the ozone concentration falls below a predetermined value, there is a risk of temperature rise, toner paper powder, silicon gas, etc., causing damage to the image forming part and temperature rise, but this is prevented by releasing a certain amount of air flow. it can. Furthermore, in order to prevent the temperature rise inside the machine and to discharge the vaporized silicon oil, it is necessary to secure the minimum exhaust air volume, but this configuration ensures the minimum exhaust volume, so it is exhausted. It is possible to suppress the amount of ozone to be kept within a predetermined value.

According to the image forming apparatus of the third aspect, ozone is naturally decomposed by a predetermined rate in a predetermined time if left standing. Therefore, if the amount of ozone discharged from the image forming apparatus to the outside of the apparatus is suppressed to a predetermined amount or less, the ozone concentration in the periphery does not exceed the desired value. Therefore, by controlling the exhaust amount of ozone to a predetermined amount or less per unit time, it is possible to control the ozone concentration around the device to a predetermined value or less.

According to the image forming apparatus of the fourth aspect, even when the sensor is abnormal, it is necessary to keep the temperature rise in the machine below a certain value, so that it is necessary to secure the lower limit air volume. On the other hand, since the ozone filter is not out of order, copying can be continued by ensuring a predetermined air flow rate. Therefore, even if the sensor is abnormal, the device can be used continuously and the operating time does not decrease.
Further, if the sensor is normal, the ozone detection amount rises above a predetermined value when the image forming process operates. However, if it is abnormal, it does not change. Therefore, the abnormality can be detected, and the amount of ozone discharged from the image forming apparatus can be appropriately controlled. When it is determined that there is an abnormality, a message indicating that the machine is abnormal is sent to notify the operator or the machine is stopped. This makes it possible to provide an image forming apparatus with high safety.

According to the fifth aspect of the image forming apparatus, the ozone removal efficiency of the ozone filter changes with temperature and humidity. Since the air flow rate control means is controlled in consideration of this change characteristic, it is possible to accurately control the ozone concentration to a predetermined value or less. That is, the temperature and humidity inside the machine change intricately depending on the temperature rise and the history of the copying process. Therefore, it is possible to improve the ozone removal performance of the ozone filter and accurately and stably control the emission amount by monitoring the temperature and humidity and adjusting the air flow rate according to the situation.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a copying machine according to the present invention.

FIG. 2 is a configuration diagram of the device of the present invention.

FIG. 3 is a configuration diagram of a filter peripheral portion of the device of the present invention.

FIG. 4 is a block diagram of an ozone sensor circuit 110.

FIG. 5 is an explanatory diagram of an ozone sensor output.

FIG. 6 is a schematic configuration diagram of an ozone sensor.

7 is another block diagram of the ozone sensor circuit 110. FIG.

FIG. 8A is a diagram showing a wind speed distribution of an ozone filter. (B) It is a figure showing the measurement conditions in (A). (C) It is a figure showing the measurement position in (A).

FIG. 9A is a diagram showing a relationship between an ozone emission concentration and an average concentration value. (B) It is a figure showing the measurement conditions in (A).

FIG. 10 is a diagram showing a relationship between an air flow rate and an ozone removal rate.

FIG. 11 is a diagram showing a deterioration state of an ozone filter.

FIG. 12 is a diagram showing a deterioration situation of an ozone filter.

FIG. 13 is a diagram showing changes over time in ozone concentration (during continuous copying).

FIG. 14 is a diagram showing changes over time in ozone concentration (at the time of making one copy).

FIG. 15A is a diagram showing a temporal change of an ozone concentration detection value. (B) It is a figure showing the time change of the ventilation volume.

FIG. 16 is a diagram showing a relationship between a first air volume and a second air volume.

FIG. 17A is a diagram showing a relationship between a copying time and an air volume. FIG. 6B is a diagram showing the relationship between the copy time and the copy interval. (C) It is a figure showing the relationship between copy time and ozone concentration. (D) It is a figure showing the relationship between copy time and machine temperature.

FIG. 18 is a block diagram of a temperature sensor circuit.

FIG. 19 is a diagram showing a relationship between an ozone removal rate and relative humidity.

FIG. 20 is a diagram showing a relationship between SV and ozone removal rate at each humidity.

FIG. 21 is a configuration diagram of a humidity sensor.

FIG. 22 is a sensor output voltage characteristic diagram.

FIG. 23 is a diagram showing a relationship between relative humidity and set air volume.

FIG. 24 (A) is a diagram showing a relationship between reaction time and ozone decomposition rate. (B) It is a figure showing the relationship between a temperature and an ozone decomposition rate. (C) It is a figure showing the relationship between an air volume and an ozone removal rate.

FIG. 25 (A) is a diagram showing a temporal change in ozone concentration. (B) It is a figure showing the time change of an air volume. (C) It is a figure showing the time change of the amount of ozone discharges.

FIG. 26 is a fan motor drive circuit diagram.

FIG. 27 is a flowchart showing the operation of the first embodiment of the present invention.

FIG. 28 is a flowchart showing the operation of the fourth embodiment of the present invention.

FIG. 29 is a flowchart showing the operation of the fourth embodiment of the present invention.

FIG. 30 is a flowchart showing the operation of the second embodiment of the present invention.

FIG. 31 is a flowchart showing the operation of the second embodiment of the present invention.

FIG. 32 is a flowchart showing the operation of the fifth embodiment of the present invention.

FIG. 33 is a flowchart showing the operation of the sixth embodiment of the present invention.

FIG. 34 is a flowchart showing the operation of the seventh embodiment of the present invention.

FIG. 35 is a flowchart showing the operation of the third embodiment of the present invention.

[Explanation of symbols]

 1 Copier main body 2 Optical system 3 CL (copy lamp) 4 Mirror 5 Mirror 6 Mirror 7 Mirror 8 Zoom lens 21 Photoconductor 22 Charger 23 Developing unit 24 Transfer device 25 Static eliminator 26 Document cover 27 Automatic document feeder 28 Document transport Path 29a Drum 29b Drum 30 Paper Feeding Section 31 Registration Roller 32 Conveying Device 33 Fixing Section 34 Ejection Tray 35 Paper Conveying Path 37 Reversing Section 40 Master CPU 41 Slave CPU 42 ROM 43 ROM 44 Operation Circuit 45 Display Section 46 Heater Lamp Lighting Circuit 47 Copy lamp lighting circuit 48 Process control circuit 49 Motor drive circuit 50 Clogging detection circuit 51 HL (heater lamp) 55 Shutter solenoid drive circuit 56 Shutter solenoid 57 Filter heater drive circuit 58 Heater 59 Work part 101 Dust filter 102 Ozone adsorption catalyst filter (ozone filter) 103 Airway 104 Fan 105 Clogging detection part 105a Wind velocity sensor 105b Encoder 105c Input current detection circuit 110 Ozone sensor circuit 111 Ozone sensor 112 Temperature sensor circuit 113 Temperature sensor 114 Humidity Sensor circuit 115 Humidity sensor 116 Comparator 117 Alarm setting trimmer 118 Output circuit 119 Amplifier 120 Transistor 1 121 Transistor 2

Claims (5)

[Claims] 1. An air blower for sucking or blowing ozone air around the image forming process to the outside of the image forming apparatus, a control means for controlling the amount of air blown by the air blower, and an ozone air flow path. The ozone filter that absorbs ozone and the ozone sensor that detects the ozone concentration when the image forming process is continuously executed for a predetermined time after the image forming process is started are arranged on the exhaust side of the ozone filter, and An image forming apparatus, wherein the air flow rate control means reduces the air flow rate when a detection signal from an ozone sensor reaches a predetermined concentration or higher. 2. When the detection signal from the ozone sensor exceeds a predetermined concentration value, the air flow rate control means reduces the air flow rate, and the air flow rate control means is provided with a lower limit value of the air flow rate. The air flow rate control is performed when the control is performed within a range not exceeding the lower limit value, and the ozone concentration is detected every predetermined time after the image forming process is started to detect that the ozone concentration is equal to or lower than the predetermined value. The image forming apparatus according to claim 1, wherein the air blowing amount is increased by means. 3. A wind speed detecting means for detecting the wind speed of the ozone air discharged by the blowing means is provided, and the ozone discharge amount is equal to or less than a predetermined value in accordance with the product of the detected ozone concentration value and the wind speed value. The image forming apparatus according to claim 1, wherein the air flow rate is controlled so that 4. The image forming apparatus according to claim 1,
Storage means for storing the output signal of the ozone sensor when the image forming process is stopped, comparison means for comparing the output signal of the ozone sensor during the operation of the image forming process with the output value stored in the storage means, and the comparison When the value compared by the means is equal to or less than a predetermined value, the ozone sensor determines that the ozone sensor is abnormal, and when the determination result indicates that the ozone sensor is abnormal, a means for setting the blow rate to the lower limit value. An image forming apparatus characterized by being provided. 5. A humidity detecting means for detecting the in-machine humidity, a temperature detecting means for detecting the in-machine temperature, an exhaust means for exhausting ozone air inside the machine through an ozone removing means, and a control means for controlling the air volume of the exhaust means. And a detection means for detecting the ozone concentration of the exhausted ozone air, the minimum air volume required for heat dissipation from the optical system or the heating means such as the fixing device is set to the first value. When the maximum air volume required for ozone removal that compensates for changes in ozone removal characteristics in a temperature / humidity environment where an ozone filter is placed is the second air volume, the air volume control device detects that the temperature detection data is equal to or higher than the predetermined temperature. When the ozone detection data is equal to or higher than a predetermined value, the second air volume is controlled, and the temperature detection data is equal to or higher than the predetermined temperature. An image forming apparatus, characterized in that, when the detected data is equal to or higher than a predetermined value, the image forming apparatus is controlled in a process of lowering the temperature inside the apparatus.