JPH01221763A - Controller for power receiving body changing output value in corresponding to environmental condition - Google Patents

Abstract

PURPOSE:To reduce the number of parts of the title controller and to simplify its electrical and mechanical constitution by providing a counting means which counts the energizing and nonenergizing hours of heating body within its prescribed tempera ture change range as hour coefficients. CONSTITUTION:A counting means 14 which counts the energizing and nonenergizing hours of the heating body within its prescribed temperature change range is provided. In other words, a control section 13 is constituted of a CPU and obtains counted value corresponding to an environmental condition where the relative humidity and air current are included in the main environmental temperature in accordance with the detect signals of a temperature detecting element 20 from a counter 14. Then the control section 13 sets, changes, or maintains aimed control values, etc., of processing means including the heater which heats a photosensitive body in accordance with the counted value. Moreover, the section 13 transmits prescribed control signals to power source circuits 21-26 side which control the applying voltage, power supply ing interval, etc., of each processing means in accordance with the aimed control values. Therefore, the number of parts can be reduced and the electrical and mechani cal constitution can be simplified.

Description

[Detailed Description of the Invention] "Industrial Application Field" The great invention is to adjust the output value from the power receiving body to a predetermined value corresponding to the environmental conditions by appropriately changing the energizing device such as the energization interval of the power receiving body or the applied voltage. It relates to a control device for a power receiving body that is configured to maintain control target values or target ranges, particularly the applied voltage and energization interval of one or more process means including an image carrier incorporated in a printer or other electrophotographic device. The present invention relates to a control device for a process means that is configured to appropriately change the output values and the like to obtain an optimum output value corresponding to environmental conditions.

``Traditional branch technique'' Conventionally, optical systems for writing latent images, development, transfer, static elimination, charging, and other process means have been arranged around photoreceptor drums and other image carriers, and Printers and other electrophotographic devices that print or record predetermined images are well known, and the image carriers used in these types of electrophotographic devices generally have temperature dependence. A heating means is attached to heat the surface temperature to a predetermined temperature to prevent fluctuations in photosensitive characteristics due to internal environmental conditions. In order to prevent this, in many cases the heating temperature of the image bearing member is controlled so as to be relatively changed in accordance with the environmental temperature inside the machine.

On the other hand, the surface potential of the latent image written by the optical system does not necessarily affect only the photosensitive characteristics of the image carrier, but also the corona discharge characteristics of a charger that uniformly charges the surface of the carrier, a static eliminator that removes residual charges, etc. . These corona discharge characteristics also have temperature dependence, so stable H
In order to obtain the s-image potential, there are some devices that compensate for fluctuations in corona current by changing the voltage along with the image carrier in accordance with the environmental temperature inside the machine.

``Problem to be Solved by the Invention'' However, the surface potential carried on the surface of a photoreceptor does not necessarily depend only on the environmental temperature, but is also influenced by the relative humidity existing around the photoreceptor. For example, photoconductors such as OPC and amorphous silicon, which have been widely used in recent years, are all highly hygroscopic, and therefore, in addition to the above-mentioned environmental temperature, the humidity inside the machine is also taken into account when heating the photoconductor. It is necessary to set target values.

On the other hand, in this car, the same applies to the charger and other process means placed around the photoconductor, and like the photoconductor, it is necessary to set the control target value of the active output by taking into account the environmental humidity inside the machine in addition to the environmental temperature. In addition, the process means may be provided with an air blowing means for removing ozone generated by corona discharge, and therefore it is also preferable to set the control target value taking into consideration the influence of these air flows.

However, in order to set control target values taking into account all such environmental conditions, each sensor such as a temperature sensor, humidity sensor, and wind sensor must be prepared according to the individual environmental conditions to be detected. Moreover, a control circuit is also required to process the outputs from each of these sensors and set desired environmental conditions, which results in an increase in the number of parts and a complicated electrical and mechanical configuration.

However, the above control cannot be performed without quantitatively determining how the relative humidity and air flow affect active outputs such as surface potential and corona discharge current, and the degree of influence also depends on the environmental temperature (temperature Since the control program changes slightly depending on the difference in temperature, the control program becomes extremely complicated.

In view of the drawbacks of the prior art, the present invention is designed to easily and accurately measure the environmental conditions, mainly the environmental temperature, with the relative humidity and airflow taken into account, without directly measuring the environmental conditions on each side. and setting a control target value or target range of the power receiver based on the measured environmental conditions;
It is an object of the present invention to provide a temperature control device for a photoreceptor that can be changed or maintained.

"Means for Solving the Problems" The present invention provides a method for applying a predetermined amount of thermal energy to an object to be heated from a heating element, and for an object that retains a predetermined thermal energy after being energized and cleaned from the heating element. When heat is removed from a heating body, even if the amount of thermal energy imparted or removed is constant, the time for the temperature rise (fall) of the heated body per unit temperature is not constant; It was developed by focusing on the fact that it varies depending on the complex factors of the surrounding environmental temperature, the temperature difference between the environmental temperature and the heated object, and the environmental humidity (hereinafter referred to as "erotic threshold temperature, etc."), and its characteristics (1) It has at least one heating element that causes a temperature change when it is continuously energized or turned off for a predetermined period of time.

In this case, the heating element is placed inside the machine that detects the environmental temperature.
For example, in an electrophotographic device, the heat generation of an element such as a laser diode of a laser printer, which generates significant heat during active recording, may be used. For example, heat generated by a pre-ignition resistor, which contributes to stable operation of LED/thermal heads, etc., may be used.

Note that energization or de-energization continuously for a predetermined period of time refers to continuous energization or de-energization during the predetermined temperature change described in section (2), and then 0N-- to maintain the predetermined control target value.
Naturally, the present invention also includes the case where OFF control is performed.

■The provision of a counting means that counts the energization or de-energization time of the heating element during a predetermined temperature change width of the heating element as a time factor.In this case, the predetermined temperature change range counted by the counting means means the heating element energization time. It is not limited to the range of temperature change from the start of energization (cutting), but also includes the range of temperature change between arbitrary points during energization (cutting).

Note that the temperature change range does not need to be a constant value over and over again, and the control section may perform count correction so that the temperature change range becomes constant.

■Based on the count value, the control target value or target range of the one or more power receivers arbitrarily selected is set, changed, or maintained.Accordingly, the object to be controlled is 1, for example, a heating element. The present invention is not limited to the attached power receiving body, but also includes a plurality of other power receiving bodies whose control target value should be changed based on the environmental conditions detected by the heating element.

In order to obtain higher accuracy, it is preferable that the counting period of the counting means be configured to be adjustable in response to fluctuations in the voltage applied to one heating element.

``Example'' A preferred embodiment of the present invention will be described in detail below by way of example with reference to one drawing. However, unless otherwise specified, the dimensions, materials, shapes, and relative arrangements of the components described in this example are not intended to limit the scope of this invention, but are merely illustrative examples. It's nothing more than that.

1 to 3 are LEs according to embodiments of the present invention.
This is an electrophotographic device using a D printer head. Figure 1 is a basic configuration diagram, Figure 2 is its control circuit diagram, and Figures 3 (a) (b).
)(c) is a flowchart showing the control II operation.

As shown in FIG. 1, an electrophotographic apparatus generally has an LED printer head 2 arranged around a photoreceptor drum 10 in the rotational direction.
, developer 3. A transfer device 4 using corona discharge, a cleaning member 5, an eraser B that removes static electricity by illumination, a charger 7 using corona discharge, etc. are provided, and in the wooden embodiment, the LED printer 12 and 2 face the LED printer. Then, a thermistor or other temperature sensing element 20 is arranged near the mounting position of the bleeder resistor RB, which contributes to the stable operation of the LE[l, and the surface temperature at a predetermined part of the rad 2 is detected in the printer depending on the heat generated by the bleeder resistor RB. It is configured to be detectable.

Note that 8 is a heater that heats the photosensitive drum 10, 8 is a recording medium to which the toner image carried on the drum 10 is transferred by the transfer device 4, and a fixing device (not shown) disposed downstream thereof. After the toner image is fixed, the paper is ejected.

Reference numeral 1 denotes a control circuit consisting of a microcomputer, and power supply circuits 21 to 2B that control the applied voltage or energization interval of each of the process means based on control target values set, changed, or held by the control circuit 1. At the same time, a display panel 27 is also connected to display whether or not there is an abnormality in each of the power supply circuits 21 to 26, and whether or not there is an abnormality in the cabin environment based on the environmental temperature detected by the detection signal.

Next, the detailed configuration of the control circuit 1 will be explained based on FIG. 2.

Control circuit 1 c. Comparator 11. DA converter 12, V
/F converter 15. It consists of a control section 13 and a counting means 14 which functions as a timer. First, the output voltage of the drive power source of the RAD 2 is sent to the LED printer by a V/F converter 15.
After inputting the voltage, the V/F converter 15 changes the count clock period sent to the counting means 14 in accordance with the voltage fluctuation of the output voltage, so that [(voltage fluctuation)×(count clock period)] is constant. It is configured so that it can be controlled to

The counting means 14 continues counting until a stop signal is input based on the clock cycle from the V/F converter 15 by inputting a start signal from the control unit 13, and also changes the count value by inputting the stop signal. is configured to be able to be transferred to the control unit 13.

The comparator 11 is connected to the control unit 13 via the OA converter 12.
Accordingly, the detection interval start/end values TI, T2 corresponding to the predetermined temperature rise width necessary for changing or maintaining the environmental conditions are determined.
The reference voltage for comparison is compared with the voltage to be compared corresponding to the temperature detected by the temperature detection element 20, and when the voltage to be compared is lower than a certain reference voltage, the on output is turned off, and when the former is higher, the output is turned off. The information is configured such that it can be transferred to the control unit 13, respectively.

The control unit 13 is composed of a CPU, and the temperature sensing element 20
Based on the detection signal detected by Power supply circuits 21 to 2 that set, change, or hold control target values, etc. of process means including a heater for heating lO, and control applied voltages, energization intervals, etc. of each of the process means based on the control target values, etc.
It is configured such that a predetermined control signal can be transmitted to the 6 side.

Next, the control operation based on this circuit diagram will be explained along with the flowchart shown in FIG.

In FIG. 3(a), first, the temperature inside the rad 2 is detected by the LED printer based on the detection signal from the temperature detection element 20, and the temperature is higher than the upper limit Ut at which the head 2 or the environmental temperature should be judged as abnormal. 5 TEP 1)
In the following cases, it is then determined whether or not the corresponding detection interval start value T1 is reached during the predetermined temperature rise. 5TEP 2) In the following cases, the drive power is turned ON and the environment temperature measurement routine is entered. (STEP 3) If the detected temperature t of the temperature sensing element 20 is equal to or higher than the detection interval start value T1, such as when restarting after a jam, etc., the environmental temperature is not measured, but is measured based on the control target value etc. stored in evacuation memory. Perform heating control (STEP
(STEP
5) Next, regarding the environmental temperature measurement routine, as shown in FIG. 3(b), the surface temperature t of the printer head 2 detected by the temperature detection element 20 by energization of the bleeder resistor RB starts the first detection period. After reaching the value T1 (ST
5TEP7) The temperature of the printer head 2 has reached the detection interval end value T2 e ( STEP8
), the count value is stopped and the count value is transferred to the control unit 13. 5TEP9)) Based on the count value, control target values for each of the process means corresponding to the environmental conditions are selected and held. (STEPlO) In this case, the count value transferred to the control unit 13 is
If the value exceeds a predetermined setting value due to a short circuit in the LE printer head 2 or other cause, the process moves to an error content detection routine. (STEP II) In the error content detection routine, as shown in FIG.
SiTEP12), Determine whether there is an abnormality on the head 2 side or the power supply circuit 21 to 26 side of the head 2 due to short circuit disconnection of the bleeder resistor RB, or an abnormality in the in-machine environment itself (STEP1O)t, Display panel 27 to that effect to be displayed. (STEP 14) Returning to 5TEP 15 in FIG. 3(a), the applied voltage or energization interval of each of the process means power sources is controlled based on the set and held control target value, etc., and the process means is adjusted to the control target value, etc. to maintain control.

If the energization control is interrupted due to a jam or the like, the drive power source is stopped after saving and storing the control target value, etc. (STEP 1B). (STEP 17) On the other hand, even if the energization control is not interrupted, the environmental temperature may change due to long-term recording operation, so measure the environmental temperature as appropriate and change or reset the control target value. S
TEP l! 9) At this time, the temperature inside the LED printer head 2 is detected based on the detection signal from the temperature detection element 20, and if the temperature is within the upper limit value at which the head 2 or the environmental temperature should be judged as abnormal, the drive power is turned off. Turn off and proceed to error content detection routine. (STEP 20) According to this embodiment, in addition to the effects of the present invention to be described later, the number of parts can be reduced because the control is performed by effectively utilizing the LED printer Hesid 2 without providing a special heating element. This leads to a smaller footprint.

Furthermore, the use of a heating element attached to a process means can also be used to detect abnormalities in the process means, and its practical effects are great.

Further, the unembodied embodiment determines the optimum control values for all other process means based on one environmental condition, and is therefore extremely advantageous in terms of image formation.

r Effects of the Invention As described above, according to the present invention, without directly measuring various environmental conditions such as temperature, humidity, or airflow, the relative Temperature sensor There is no need to install each sensor such as a humidity sensor, wind sensor, etc. individually, and there is no need for a control program or control circuit to process the output from each sensor and set environmental conditions. As a result, the number of parts can be reduced and the electrical and mechanical configuration can be extremely simplified.

It has various effects such as

Therefore, the present invention is particularly effective as a control device for an electrophotographic apparatus in which a control target value must be set taking into account not only environmental temperature but also environmental conditions such as relative humidity.

[Brief explanation of the drawing]

1 to 3 all relate to embodiments of the present invention; FIG. 1 is a basic configuration diagram, FIG. 2 is a control circuit diagram thereof, and FIG.
a), (b), and (c) are flowcharts showing temperature control operations.

Claims (1)

[Claims] One or more power receiving devices configured to be able to maintain the output value from the power receiving device at a predetermined control target value or target range corresponding to environmental conditions by appropriately changing the energization interval of the power receiving device or the amount of energization such as the applied voltage. In a control device for a power receiving body, at least one heating element causes a temperature change by continuously energizing or cutting off electricity for a predetermined period of time, and energizing or cutting off electricity to the heating element during a predetermined temperature change width of the heating element. and a counting means for counting time as a time coefficient, and setting, changing or maintaining a control target value or target range of the arbitrarily selected one or more power receiving bodies based on the count value. Features of power receiver control device