JPS58147770A - Dew condensation alarm device of copying machine - Google Patents

Abstract

PURPOSE:To remove or avoid a dew condensation of a device, by discriminating whether the dew condensation is generated or not, by a detecting value of each sensor for detecting a temperature of a roll surface part and a temperature and humidity of an atmosphere in the vicinity of the roll. CONSTITUTION:A roll temperature sensor 4 is provided so as to contact with the circumferential surface of the end part of a lower roll 2, and in the vicinity of the lower roll 2 being adjacent to the sensor 4, an atmospheric temperature sensor 5 and an atmospheric humidity sensor 6 are provided. A detecting value by each sensor is inputted to an information processing part 7, whether a dew condensation is generated or not is discriminated by use of a dew condensation generating condition data which is given as a data in advance, and if a condition for generating dew condensation is ready, an alarm is raised. In this way, when an operator makes a device execute running-in until the alarm lamp goes out, the dew condensation of the device is removed, and a good copy can be obtained without waste.

Description

[Detailed description of the invention] The present invention relates to a dew condensation warning device for a copying machine.

In a copying apparatus equipped with a roller fixing device, dew condensation may occur on the surface of the roller constituting the fixing device due to a temperature difference with the ambient temperature. Since this impairs copy quality, it has become common knowledge in the industry since around 1975 to install a dew condensation prevention device on copying machines.

The following six techniques are known as conventional dew condensation prevention means.

(1) Use materials that do not easily form condensation.

(2) Warm up the machine using heat retention means.

(31 Make the temperature inside the aircraft the same as the ambient temperature.

Among the above technologies, there are still many unresolved problems regarding (]) (21* (For 31, an external heat source is required, such as surface heaters, positive temperature thermistors, cast heaters, pipe heaters, hot air blowers, etc.). However, in both cases, consideration must be given to toner blocking due to high temperatures and static electricity due to abnormal internal drying, which poses problems such as the need to set a thermostat or take other fire prevention measures. be.

Further, since dew condensation mainly occurs in the winter season, and the above-mentioned heat source and accompanying equipment are not necessary in other seasons, some kind of countermeasure is desired.

The inventor of the present invention has discovered that even if dew condensation occurs in areas other than cold regions, a relatively short break-in operation will reduce the amount of heat generated by the exposure light source or the friction between the rollers. It has been found that dew condensation can be eliminated by heat, etc. In other words, if the conditions for condensation to occur are met, the operator can be informed of this in advance, and if they are made aware of the break-in operation, condensation can be eliminated and incorrect copies can be avoided. .

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a dew condensation warning device for a copying machine that provides guidance as to whether or not to perform a break-in operation to eliminate or avoid condensation.

The present invention will be explained in detail below.

A dew condensation alarm device for a copying machine according to the present invention includes a roller temperature sensor that detects the temperature of the roller surface, an ambient temperature sensor that detects the ambient temperature near the roller, and a humidity sensor that detects the ambient humidity near the roller. An information processing unit that determines whether or not condensation has occurred using the detection values from each of the above sensors and condensation generation condition data given in advance as data, and an alarm that issues an alarm regarding the occurrence of dew condensation based on the calculation result of this information processing unit. It is characterized by having means.

FIG. 1 shows an example of a roller fixing device in a copying machine. In the figure, numeral 1 is an upper roller, numeral 2 is a lower roller,
Reference numeral 3 indicates a housing.

Next, FIG. 2 shows the arrangement positions of various sensors used in carrying out the present invention. For example, a contact type roller temperature sensor 4 is placed in contact with the peripheral surface of the end of the lower roller 2. It is a provision. The roller temperature sensor 4 has mechanical strength to withstand rotational wear and hardness to the extent that the roller is not damaged. The roller temperature sensor 4 used has an applicable range of approximately 0°C to 100°C. Note that, unlike the above example, the roller temperature sensor 4 may be provided in contact with the upper roller 1.

Next, an atmospheric temperature sensor ~5 for detecting the atmospheric temperature in the vicinity of the lower roller 2 is provided at a spatial position within several U from the roller surface location measured by the roller temperature sensor 4. The ambient temperature sensor 5 used has an applicable range of 0°C to ioo°C.

Next, a humidity sensor 6 for detecting atmospheric humidity is disposed at a spatial position very close to the atmospheric temperature sensor 5. For example, the tip of this humidity sensor 6 is made of Zn.
O,0r205. A humidity sensing element such as Fe2O3 is incorporated, and changes in humidity are converted into changes in electrical resistance and output. The humidity sensor 6 used has an applicable range of relative humidity of 0% to 100%.

The detection results from each of these sensors are input to the information processing unit 7, which processes the information and issues an alarm when the conditions for condensation to occur on the rollers are met, prompting the operator to adjust the equipment. This is to encourage people to drive more slowly. Note that the symbol S indicates a recording paper immediately after development, which is the object to be fixed, and is fixed by the pressure applied by the upper and lower rollers.

The configuration of the information processing section 7 is shown in FIG. In FIG. 3, an electrical signal containing temperature information of 01° C. related to the peripheral surface temperature of the lower roller 2 detected by the roller temperature sensor 4 is input to an operational amplifier 8.

Similarly, maintain the ambient temperature near the lower roller 2, which is the heat source, detected by the ambient temperature sensor 55. An electric signal i containing temperature information θ2"C is also input to the operational amplifier 8. Furthermore, an electric signal containing humidity information RH% related to the atmospheric humidity near the lower roller 2, which is a moisture source, detected by the humidity sensor 6 is inputted to the operational amplifier 8. A signal is input to operational amplifier 8TIc.

Then, in the operational amplifier 8 to which the above electric signals are input, θ,
-02--〇 calculation is executed to detect the temperature difference between the roller surface temperature and its neighboring temperature. And the above RH
, jθ, etc. are amplified and converted into digital values by an A/'D converter 9, and then sent to a microprocessor 10 &?
: Input.

Here, the microprocessor 10 has a ROM section having a dew condensation condition table to be described later, a control program section and a RAM section for comparing and determining the dew condensation condition value and the actual measured value, and acts as an alarm means based on the determination result. For example, the alarm rung is turned on, and the precept outputs an alarm signal to turn it on. This alarm signal is input to the lamp controller 12 via the D/'A converter 11. The lamp controller 12 turns on or off a warning lamp that warns of the occurrence of condensation in accordance with the instructions of the signal.

By the way, the above-mentioned dew condensation condition table is based on a well-known psychrometric diagram as shown in FIG. 4, and various data shown by this diagram are stored in memory.

The following cases can be considered as cases in which condensation occurs.

For example, suppose that during the cold winter season, it is necessary to turn on the copying machine and copy immediately at the same time as heating the room temperature. Then, although the room temperature rises rapidly due to the heating device, the temperature of the fixing roller does not rise as rapidly, so a temperature difference occurs between the roller circumferential surface and the surrounding space, and for example, the relative humidity at this time is RH - 60%. , assuming that the ambient temperature θ2=25°C, the temperature difference Δθ−86θg or more, that is, the roller temperature θ
, dew condensation will occur in the range of 17°C or lower. but,
Even if such conditions for condensation are met, the operator cannot easily know it. Even though the condensation is eliminated by a slight break-in operation, copying is performed and a defective copy due to the condensation is produced.

According to the present invention, the above-mentioned problem is solved because the situation of dew condensation is automatically displayed.

An example of a process for carrying out the invention is shown in FIG. To explain according to the diagram, in the process P1, the microprocessor 10 of FIG. 6, roller temperature θ, ambient temperature θ2. Each measurement value 1 such as relative humidity RH is input. Then, in process P2vC, the ambient temperature θ2 and relative humidity RH are specified, the condition table is read, and the temperature difference ΔθTa for condensation under those conditions is read. Next, in process P3, actual temperature differences θ2-θ and -ΔθACT are calculated based on the measured values.

Next, in process P4, the temperature difference Δθ is increased. . , and when the ambient temperature θ2 is higher than the roller temperature θ and when both are equal for safety, the next process P5VC is advanced, and the temperature difference for condensation -〇, the size relationship with a is determined. be judged. Then, when the measured temperature difference ΔθAoT is equal to or larger than the condensation temperature difference ΔθTa, in process P6, A=
1, the lamp is commanded to turn on in process P7. In addition,
Measured temperature difference Δθ,. 1 is the condensation temperature difference Δθ, smaller than 1
・When there is no condensation, A=OK in process P8.
After that, a command to turn off the lamp is issued in process P.

As explained above, according to the present invention, it can be easily determined whether or not there is a dew condensation condition. Therefore, if the conditions for condensation are satisfied, if the break-in operation is performed so that at least the warning lamp goes out, the condensation will be eliminated and good copies can be obtained without wasting anything.

[Brief explanation of drawings]

FIG. 1 is a side view explaining an example of a fixing device, FIG. 2 is a perspective view of the fixing device portion explaining the present invention in detail, FIG. 3 is a diagram explaining an information processing path, and FIG. psychrometric chart,
FIG. 5 is a diagram explaining the information processing process. 4...Roller temperature sensor, 5...Ambient temperature sensor, 6...Humidity sensor, 7...Information processing section. Chicken 1 Price

Claims (1)

[Claims] A copying apparatus equipped with a roller fixing device includes a roller temperature sensor that detects the temperature of the roller surface, an ambient temperature sensor that detects the atmospheric temperature near the roller, a humidity sensor that detects the atmospheric humidity near the roller, and each of the above. an information processing unit that determines whether or not condensation has occurred using a value detected by the sensor and condensation generation condition data given as data in advance; and an alarm means that issues an alarm regarding the occurrence of condensation based on the calculation result of the information processing unit. A dew condensation alarm device for a copying machine, comprising: