JP2624732B2 - Safety device for image forming equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a safety device for an image forming apparatus such as a copying machine.

2. Description of the Related Art In general, a copying machine or the like is provided with a charging charger or the like.
Ozone, which is a harmful substance, is generated by AC discharge. With respect to such ozone, there is a safety standard value for the amount of generated ozone in order to prevent environmental pollution. It is necessary to suppress the generation of ozone so that the amount of ozone leaked to the outside is equal to or less than a reference value.

In this regard, in a copying machine or the like, the fan is constantly driven to rotate while the power is on, that is, during operation, and a cooling and discharging operation is performed for the heat generated by the exposure lamp and the like. An ozone filter is provided in such a cooling fan, and the amount of ozone discharged to the outside by exhausting air through the ozone filter is set to a predetermined value or less. However,
If the cooling fan stops due to a malfunction of the cooling fan or a break in the wiring code of the cooling fan during the operation of the copier, only natural convection occurs in the exhaust air, reducing the efficiency of the ozone filter and causing charging. Ozone generated by discharge of the charge or the like cannot be efficiently treated. If the copying operation is continued in such a state, the ozone generation amount will exceed the safety standard value.

It is an object of the present invention to provide a safety device for an image forming apparatus capable of ensuring prevention of ozone contamination even in an abnormal situation such as a stoppage of a fan.

Configuration In order to achieve the above object, the present invention provides an image forming apparatus having an ozone removing section using a fan with an ozone filter in an exhaust path to prevent exhaust of ozone generated in the apparatus to the outside. In the safety device, a main relay is provided in a power supply circuit of a main motor of the device body, a temperature fuse is provided in the exhaust path, and the temperature fuse is connected in series to the main relay or the circuit of the main motor. It is characterized by the following.

Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 to 3. This embodiment is applied to a copying machine, and as shown in FIG. 2, a fixing unit 2 provided with a fixing roller 1 having a fixing heater is provided on a paper discharge side of a photoconductor (not shown). I have. An air passage 4 partitioned by a sheet metal member 3 is formed above the fixing unit 2. A fan 5 is provided in such a ventilation path 4,
It is configured such that the intake air from the photoreceptor side provided with a charging charger, a separation charger and the like is exhausted from the exhaust port 6 constituting an exhaust path to the outside of the apparatus. Here, an ozone filter 7 acting as an ozone removing unit is provided on the intake side of the fan 5. A temperature fuse 9 acting as an excessive temperature rise prevention member is provided at an exhaust port 6 on the exhaust side of the fan 5 via a heat radiating plate 8.

On the other hand, as shown in FIG.
10 is the relay contact 11 of the main relay 11 for 100 VAC power supply
Connected through a. In addition, the temperature fuse 9
Is connected between the + 24V power supply and the main control board 12 as an off means. The main relay 11 is connected to the main control board 12. Also, the main control board
An operation / display unit 13 is connected to 12.

In such a configuration, in the copying machine, the fan 5 is constantly rotating while the power is on, so that the cooling air flows in the ventilation passage 4 and is exhausted from the exhaust port 6 to the outside of the machine. At this time, the ozone generated by the discharging operation of the charger is discharged to the ozone filter 7.
, And is absorbed by the filter to prevent discharge to the outside of the machine. In such a normal operating state, the temperature of the temperature fuse 9 attached to the radiator plate 8 is substantially the same as the temperature of the exhausted air. Generally,
During continuous copying, the temperature rises by about 15 ° C. compared to outside air.

However, when the fan 5 is stopped due to a failure or disconnection, the cooling air does not flow in the machine and only natural convection occurs, so that the temperature inside the machine increases. In particular, as in the present embodiment, the temperature of the temperature fuse 9 disposed on the sheet metal member 3 immediately above the fixing unit 2 immediately rises to a temperature substantially equal to the temperature of the fixing unit exterior. This temperature is generally
It is around 90 ° C in a 25 ° C environment. That is, there is a large temperature difference between the case where the fan 5 is driven and the case where the fan 5 is stopped, and the temperature fuse 9 is cut off when the temperature rises due to the stop of the fan 5. When the temperature fuse 9 is cut off, the main relay 11 is not energized by the detection and control by the main control board 12, and the relay contact 11
a is released. Therefore, the main motor 10 is also stopped,
When the fan 5 is stopped, the copying operation cannot be continued, and the apparatus is brought down. As a result, generation of ozone is eliminated, and ozone is not scattered outside the apparatus as in the continuous operation. The operation / display unit 13 indicates that the device has been down due to the stoppage of the fan 5.

The relationship between the time and the temperature of the temperature fuse 9 will be described with reference to FIG. In the figure, time t ₀ is when the fan 5 is stopped, time t ₁ is when the temperature of the temperature fuse 9 is reached,
Time t ₂ respectively indicate when the temperature Hiyuzu 9 has expired. Also,
Since the operating temperature of a general copying machine is 10 to 30 ° C., the temperature fuse 9 reaches the maximum temperature during normal use during continuous copying at an operating environment temperature of 30 ° C., which is approximately 45 ° C. (at the upper limit). And is indicated by a two-dot chain line in FIG. 3). The lower limit is the characteristic indicated by the one-dot chain line in FIG. The lowest temperature when the fan 5 is stopped in the abnormal mode is a case where the use environment temperature is 10 ° C. However, since the fixing temperature control is not performed, there is almost no difference between the respective use environment temperatures. It is.

In consideration of such points, the set temperature of the temperature fuse 9 may be basically any value as long as the value is in the range (45 to 85 ° C.), but in order to ensure safety, 45 ° C. and 85 ° C. The intermediate temperature is preferably about 70 ° C., and is set to 70 ° C. in this embodiment.

Further, when the thus quickly cutting temperature Hiyuzu 9 at time t ₁ has reached the set temperature, as well shall apply in the case of turning off immediately the power supply switch after continuous copying (normal) shown by a broken line in FIG. 3 temporarily becomes off temperature Hiyuzu 9 at time point t ₁ in the middle to rise above the preset temperature of the temperature Hiyuzu 9 in. Therefore, when the temperature fuse 9 actually cuts off
By providing the time t ₂ ~t ₁ becomes delay time until t _2, the normal operating normally at the time of use, when the abnormal mode only abnormal temperature rises Juan 5, including during continuous copying
Is stopped, the main relay 11 is also stopped. Here, in general t ₀ ~t ₁ becomes time is 10 minutes, t ₁ ~t ₂ becomes time is usually 20 minutes.

Next, a second embodiment of the present invention will be described with reference to FIG. In the above-described embodiment, when the fan 5 stops, the main relay 11 is turned off based on the operation of the temperature fuse 9 (as a result, the main motor 10 is also turned off). When the fuse 9 runs out, the main motor 10 is directly turned off.

Effect As described above, the present invention relates to a safety device of an image forming apparatus that has an ozone removing unit using a fan with an ozone filter in an exhaust path and prevents exhaust of ozone generated inside the apparatus to the outside. Since a main relay is provided in the power supply circuit of the main motor of the apparatus body, a temperature fuse is provided in the exhaust path, and the temperature fuse is connected in series to the main relay or the circuit of the main motor. It is possible to reliably prevent the ozone from being scattered by continuing the operation while the operation of the system is stopped.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention, and FIG.
FIG. 3 is a schematic side view, FIG. 3 is a characteristic diagram, and FIG. 4 is a block diagram showing a second embodiment of the present invention. 6 exhaust path, 7 ozone removal section, 9 excessive temperature prevention member, 10 main motor, 11 main relay,
12 ... Off means

Claims (1)

(57) [Claims] 1. A safety device for an image forming apparatus, comprising an ozone removing unit using a fan with an ozone filter in an exhaust path to prevent exhaust of ozone generated in the apparatus to the outside of the apparatus. An image forming apparatus, wherein a main relay is provided in a power supply circuit of a main motor, a temperature fuse is provided in the exhaust path, and the temperature fuse is connected in series to the main relay or the circuit of the main motor. Equipment safety device.