JPS6361666B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wait display device for a copying machine or the like having a preparation time (hereinafter referred to as wait time).

A copying machine having a heat fixing device will be described below as an example.

In this type of copying machine, the temperature of the fixing device is low when the power is turned on, so that fixing failure occurs even when copying starts. For this reason, conventionally, a wait lamp was turned on while the temperature was rising to prohibit copying, and to enable copying after detecting that the fixing temperature had been reached.

However, this wait time can take as long as 3 minutes depending on the copying machine, so waiting for the wait to complete feels extremely long for the operator, and it is also completely unclear how much wait time there is until the wait is up. For some reason, I was often extremely uncomfortable when the copier started up.

The object of the present invention is to provide a weight display device that eliminates the above-mentioned drawbacks and allows comfortable copying operations.

That is, the present invention provides, in an image forming apparatus having a fixing device such as a copying machine, a detection means (temperature detection circuit 1) for detecting the initial temperature of the fixing device during a time period after the power is turned on when image formation is not possible. , a setting means (binary/decimal conversion circuit 6) for determining and setting a waiting time until image formation becomes possible based on the detection result of the detecting means; and displaying the waiting time set by the setting means. a display means (display 11); a subtraction means (subtraction decimal counter 7) for counting the time and subtracting the set waiting time; and displaying the waiting time subtracted by the subtracting means. It is characterized by having a control means (subtraction decimal counter 7, display 11).

Examples will be described below with reference to the drawings.

FIG. 1 is a sectional view of the copying machine, and shows the photosensitive drum 2.
While rotating the drum 2, the latent image formed on the drum 2 is developed, transferred to a transfer paper 31, and thermally fixed by a fixing roller 30, and the process is repeated a preset number of times.

Further, a thermistor is provided to detect the temperature of the roller 30 in contact with or without contact with the roller.

Figure 2 is a plan view of the operation section of Figure 1, and SW
is the main switch that turns on the device, CPB,
STOP is a key to start or interrupt copying, 13 is a lamp that displays a wait, 11 is a 7-segment LED display that displays the number of copies preset by the numeric keypad 42, and after copying starts, displays the number subtracted by -1 from the preset number. It is a vessel. The number of presets using the numeric keypad 42 is wait lamp 1.
The input can be set even while the number 3 is lit, and the number can be stored in the memory.

FIG. 3 shows a control circuit for detecting the temperature of the fixing device and displaying the time required until the wait rises.

In the figure, 2 is the fuser thermistor, 1 is thermistor 2
3 is an infrared lamp installed in the fixing roller of the fixing device, and 4 is a lamp 3 to keep the temperature of the fixing device constant.
Thermistor 2 is a temperature control circuit that controls the energization of the thermistor 2.
responds to the thermistor 2 to keep the detected temperature constant. 5 is a circuit that converts the output of circuit 1 into 8-bit A/D, 6 is a circuit that converts it to BCD, 7 is a subtraction counter, 12 is a capacitor for detecting when the power is turned on, and 11' is an output controlled by the capacitor. 8 is a circuit that drives the segment display 11; 9 is a circuit that divides the signal of the oscillator 10 and inputs it to the counter 7; a circuit 14 that divides the signal from the oscillator 10 and inputs it to the counter 7; 13 is a wait lamp; 16 is a flip-flop that controls the lamp 13 and the multiplexer 15;

The temperature of the fixing device is detected by thermistor 2,
The temperature detection circuit 1 converts it into a voltage V according to the temperature. The temperature signal converted into a voltage is converted into an 8-bit digital signal by an A/D conversion circuit 5. In this example, the temperature detection range is 0℃~
The temperature is set at 200°C, and the A/D conversion can resolve 0 to 200°C into 8 bits, and the resolution can be up to about 0.8°C per bit.

Next, the 8-bit binary signal is converted into a 10-bit BCD signal by a binary-decimal conversion circuit 6, and outputted to a preset input of a subtraction decimal counter 7.

The output of the operational amplifier 11' when the power is initially turned on is:
Since there is no charge in the capacitor 12, it is in the 0 state, so the LOAD input of the subtracting decimal counter 7 becomes 0 and the preset value by the circuit 6 is set in the counter. When the capacitor 12 is charged, the output of the operational amplifier 11' becomes 1, and the counter 7 starts subtracting.

The value of the counter 7 is sent to the 7-segment LED 11 by the display driver 8 via the multiplexer 14.
displayed as a number. Note that the multiplexer 14 selects either the counter 7 or the copy data 15 according to the control signal α.
Switch the output. oscillated by oscillator 10
Since 1MHz is divided into ^1/106 by the frequency dividing circuit 9, the clock input to the counter is 1Hz,
The counter 7 will count down once every second.

When the counter 7 counts up (0), the flip-flop 16 is reset, the wait lamp 13 is turned off, and the control signal α is set to 1 in the multiplexer to output the copy data 15 to the driver 8. When the copy start key is turned on, a control signal β is outputted to a copying machine sequence control section (not shown) to start a copy operation.

The temperature signal detected by the temperature detection circuit 1 is also input to a temperature control circuit 4, which is designed to keep the temperature of the fixing device constant. The A/D converter 5 was a Teledyne AD8700, the binary-decimal converter 6 was a TI SN74185, the data switch multiplexer 14 was an SN74157, and the counter 7 was a TI Co.
Can be configured with SN74168 etc.

By the way, it has been found through experiments that the characteristic diagram of the temperature rise after the heater power is turned on for a fixing device with a heater of 1 KW is as shown in FIG. In other words, the rising line up to the fixable temperature of 155° C. is approximately linear even under various atmospheres.

Therefore, when the temperature when the switch SW is turned on is generally an indoor temperature of 20 to 25 DEG C. (A), the converter 6 presets the counter 7 with a value corresponding to a wait time of 2 minutes. In this case, by adjusting the offset and gain of the A/D converter 5 in order to set the preset value to count a slightly longer time than the true wait-up value, it is possible to copy at the same time as the count-up. Also, if the copy key is turned on while waiting, copying can be started automatically by waiting up.

If the above characteristic diagram takes 3 minutes to reach 155°C when the atmosphere in the room where the copying machine is left is close to 0°C, such as during winter, set the converter 6 to preset that value in the counter 7 in advance. I'll keep it.

Also, when copying is complete, turn off the power, shut off the heater, and turn on the power again after several 10 minutes to start copying, for example, when 80°C (B) is detected, the number of wait times equivalent to over 1 minute is is preset in the counter 7 via the converter 6.

The preset number as described above is displayed in seconds on a 3-digit 7-segment display. For example, A
In this case, 120 is displayed and blinks. As the temperature rises, the output of the converter 6 changes from moment to moment.
The changing state is displayed on the display 11, and when it reaches 000, the flip-flop 16 is reset and the display 11 is automatically switched to display the set copy number using the numeric keypad.

As a means of displaying the remaining wait time,
Three types of dedicated different color LEDs are installed on the operation section shown in Figure 2.
The first LED (red) can be flashed for a long time, the second LED (orange) can be flashed for the middle time, and the third LED (yellow) can be flashed for the remainder of the recording time. This is made possible by operating each LED with a predetermined output of the converter 5 or 6.

Also, when the remaining time becomes short time mode with 10 seconds,
The buzzer is activated when the existence of a document on the document table is detected, or when the copy key is turned on while waiting.
Or activate the speaker to notify "Ready OK".

Next, a second embodiment using a microcomputer will be explained with reference to FIG. 5. The temperature of the fixing device is detected by a thermistor 51, and the temperature detection circuit
0, it is converted into a voltage corresponding to the temperature. The temperature signal converted into a voltage is converted into an 8-bit digital signal by the A/D conversion circuit 53 as described above, and then the temperature signal converted into a digital signal is inputted to the microcomputer 54. The microcomputer 54 compares the initial temperature with the set reached temperature, calculates how many minutes after which the weight will increase based on the temperature rise characteristic diagram, and displays the number of hours on the display 55. The microcontroller has a memory ROM ₁ in which routines for computation and display control for this comparison are programmed, and according to the memory program, outputs are output from output ports θb, θn, θk and θc, and display and display are performed.
Prohibit copying. Furthermore, the microcomputer 54 has a memory ROM ₂ programmed to subtract the number displayed on the display 55 every second or every fixed period of time, and when it reaches 0, waits up and makes copying possible.
According to the memory program, the output port θn,
An appropriate signal is output from θk. Furthermore, microcontroller 54
It also has a program memory for controlling the energization of the heater 52 on and off using a triax 58 in response to the temperature change detected by the thermistor 1 after the end of the wait to maintain a constant temperature, and outputs an on/off signal from the port θa according to the memory. . ROM ₂ displays the number of copy sets on the display 55 after waiting,
It has a program for switching to count display and automatically switches the number display.

By the way, if the temperature rise characteristic diagram in Figure 4 during a wait is not a straight line but approximately corresponds to a certain mathematical formula such as a logarithmic line, the remaining time can be easily and accurately displayed by calculating the remaining time using a computer program. Can be done.

Also, an A/D converter 53 is built into the microcomputer 54,
Furthermore, if the microcomputer 54 is configured as a one-chip semiconductor LSI, the remaining wait time can be displayed in a general-purpose manner using a conventional numeric display.

Particularly in liquid development transfer copying machines, it takes a great deal of preparation time to moisten and clean the photosensitive drum. This time also takes longer as the time for leaving it after copying is longer. Therefore, the preparation time can be determined by determining how many hours have passed since the end of copying when the power is turned on, and in this case, the time can be displayed in the same way as described above. That is, the standing time is determined by detecting the voltage of the discharge state of the capacitor or by detecting the degree of sedimentation of the toner in the developer solution by the transparency, and the wait time required for the front rotation cleaning of the drum is set, and the number is displayed in segments. While the wait is in progress, the remaining wait time is displayed.

As explained above, according to the present invention, the waiting time from the initial temperature of the fixing unit until image formation is possible is set, and the set waiting time is displayed, so that the operator can perform copying operations comfortably. I can do it. Moreover, after the waiting time is set based on the initial temperature of the fixing device, the set time is subtracted and displayed, so it is possible to provide a weight display device with a simple configuration.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a copying machine to which the present invention can be applied;
FIG. 2 is a plan view of the operating section in FIG. 1, FIG. 3 is a control circuit diagram of the weight display device according to the present invention, FIG. 4 is a rise characteristic diagram of the fixing temperature, and FIG. 5 is another control circuit diagram. In the figure, 2 is a thermistor, 3 is a heater, and 11 is an indicator for the remaining time of the weight.

Claims (1)

[Scope of Claims] 1. In an image forming apparatus having a fixing device such as a copying machine, there is provided a detection means for detecting the initial temperature of the fixing device during a time period when image formation is not possible after power is turned on; A setting means for determining and setting a waiting time until image formation becomes possible based on the detection result; a display means for displaying the waiting time set by the setting means; and a display means for counting time and displaying the set waiting time. A weight display device comprising: a subtraction means for subtracting time; and a control means for displaying, by the display means, the waiting time subtracted by the subtraction means.