JPH0324673B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a copying machine, and in particular, a resistive heater, a
The present invention relates to a copying machine equipped with a fixing device that uses a slow-starting heater element, such as an infrared heater, as a heat source.

[Conventional technology]

In this type of copying machine, copying is not possible until the temperature of the fixing device reaches a predetermined value or higher, and the print key is normally lit in red. When the temperature of the fixing device exceeds a predetermined value and each part becomes ready for copying, the print key lights up in green and copying becomes possible.

JP-A No. 53-106053 discloses that when the heater temperature reaches a first set value, a ready lamp and a small number of copies available indicator light are turned on, and when the heater temperature reaches a second set value, a small number of copies available indicator light is turned on. A technology for turning off lights is disclosed.

Furthermore, Japanese Patent Laid-Open No. 55-22774 discloses that a first time period until the temperature detected by a fixing temperature sensor indicates a copyable temperature value is measured, and a ready lamp is turned on after a second time period associated with the first time period. A copy ready display is disclosed.

Furthermore, in Japanese Utility Model Application No. 52-51181 (publication of Utility Model Application No. 53-147143), a timer circuit is configured with a capacitor charging/discharging circuit, and while the fixing heater is on, the capacitor charging/discharging circuit is charged, and the copying machine power supply is turned off. A signal generating circuit is disclosed that discharges a capacitor charging/discharging circuit at a predetermined long time constant when the capacitor is turned off, and generates a copy ready (ready lamp lights) signal when the capacitor charging voltage exceeds a set value corresponding to a copy OK fixing temperature. .

In any of the above conventional techniques, the operator cannot know in advance how long it will take to reach the fixing ready state. In other words, it is not known how long to wait before fixing, that is, copying is possible. Operators cannot make effective use of their time and have difficulty concentrating on other tasks because they have copying tasks in mind. Therefore, it is desirable to display the waiting time until the fixing device heats up.

One of the technologies related to the display of waiting time was published in Japanese Patent Publication No.
Publication No. 54-149045 discloses this. This is related to a microwave oven, and the required heating time of the microwave oven is calculated and displayed according to the food type and food amount input from the outside, and the heating is automatically activated during this heating time. However, this is done only immediately after the external input is received, and the remaining waiting time at each point after the start of heating is unknown. Furthermore, this display is a display of cooking time, which corresponds to the copying time when associated with a copying machine, and it seems difficult to imagine that it would be associated with the heat-up time of the fixing device. If this technology were applied to the waiting time display of a copying machine equipped with a fuser, the waiting time would be displayed immediately after the power is turned on, but as time elapses (the fusing temperature rises), the remaining waiting time will be displayed. Even if the waiting time decreases, the display remains the same as before, so the remaining waiting time is virtually unknown.

Furthermore, although JP-A-54-86832 discloses the calculation of the heating time in a microwave oven, there is no information regarding its display, and the heating time is the required heating time (the time from the start to the end of heating). This does not represent the remaining time required after heating starts. Furthermore, the technique involves deriving the cooking time, which corresponds to the copying time of a copying machine, and it is difficult to imagine that it corresponds to the heat-up time of the fixing device.

[Problem to be solved by the invention]

In order to represent the remaining required time, it is preferable to calculate the required heating time, start heating, and then subtract the elapsed time from the required heating time as time passes, and update and display the remaining value. However, in this way, the time required for heating only once (initial value)
In the mode in which the remaining waiting time is updated by calculating the value and subtracting the elapsed time based only on that value, there may be a temperature (initial temperature) detection error when calculating the initial value, a time calculation error, or a fixing error for each copying machine. Calculation errors due to variations in device temperature rise characteristics, fluctuations over time, fluctuations in power supply voltage, etc., and temperature deviations due to changes in the situation after calculation, remain as display errors until the remaining wait time is displayed as zero. However, as the remaining waiting time becomes shorter, the display error with respect to the actual remaining waiting time increases.

The present invention updates and displays in numerical form the remaining waiting time from time to time until the fixing heater section reaches a predetermined fixing temperature in a copying machine, and prevents initial temperature detection errors, time calculation errors, and fixing errors for each copying machine. Initial value calculation errors due to variations in chamber temperature rise characteristics, fluctuations over time, fluctuations in power supply voltage, etc., and display errors due to changes in conditions after calculation are carried over as is until the remaining wait time is displayed as zero. The purpose of this invention is to reduce a relatively large display error with respect to the actual remaining waiting time.

[Means to accomplish the task]

In the present invention, in a copying apparatus having the fixing heater 1, a temperature sensor (NTC) that generates an electric signal corresponding to the temperature of the fixing heater 1; A that converts the electric signal generated by the temperature sensor (NTC) into digital data; /D conversion means (MCP) repeats in chronological order, and calculates each time until the temperature of the fixing heater section at each time point indicated by the digital data at each time point converted by the A/D conversion means reaches a predetermined fixing temperature. a temporal data processing means (MCP) for deriving data representing;
and a character display 4 that updates and displays the time indicated by the derived data in numerical form each time the time data processing means (MCP) derives data indicating the time. Note that symbols inside brackets indicate corresponding elements in the embodiments shown in the drawings and described later.

[Effect]

The time data processing means MCP repeatedly reads temperature data (digital data) in time series and derives data indicating the time until the temperature of the fixing heater section indicated by the data reaches a predetermined fixing temperature, that is, the remaining waiting time. Therefore, the remaining waiting time corresponding to each moment of the temperature of the fixing heater part corresponds to the temperature rise of the fixing heater over time.
derived iteratively. Since the character display 4 updates and displays the time derived by the time data processing means MCP in numerical form, the time display on the character display 4 shows the remaining waiting time determined by the momentary temperature of the fixing heater section. It will be displayed.

Therefore, at any point in time until the fixing heater reaches the fixing temperature, the operator can clearly see how long he should wait until the fixing heater reaches the fixing temperature.

For example, if the initial waiting time immediately after the power is turned on is calculated to be 5 minutes (300 seconds), and assuming that the error rate is 10%, there is an error within ±30 seconds for these 5 minutes. Assuming that these 5 minutes are the starting point, and then the elapsed time is subtracted from 5 minutes every second, and the remaining value is updated and displayed, the display will be displayed when the fusing heater temperature reaches the fixing temperature. is ±
It will be within the range of 30 seconds, and as time passes from the time when the initial value of the waiting time is calculated, the error rate of the displayed value with respect to the actual waiting time will increase, and the smaller the actual waiting time, the smaller the actual waiting time. This presents the problem of large display errors.

However, in the present invention, as described above, the temperature is read repeatedly in chronological order, and each time the temperature is read, the time required for the temperature to reach a predetermined fixing temperature is calculated, and this is updated and displayed on the character display. Assuming that the error rate of the time calculation is 10% as mentioned above, and calculating the initial waiting time as 5 minutes, the display error at that time is within ±30 seconds, but for example, if the temperature of the fusing heater is the set value. Display error is ±3 30 seconds before
within seconds, within ±2 seconds before 20 seconds, within ±1 second before 10 seconds, etc., and as the temperature approaches the fixing temperature, large display errors no longer occur.

The objects and characteristics of the values of the invention will become clearer from the following description of embodiments with reference to the drawings.

〔Example〕

FIG. 1 shows a system configuration of an embodiment of the present invention. In FIG. 1, 1 is a fixing heater, and this heater 1 is connected to a commercial AC power source via a triax. The triax is combined with a photocoupler to form a solid state relay SSR.
The temperature of the fixing heater is detected by a thermistor NTC. The voltage according to the resistance value of the thermistor NTC is sent to the microcomputer via the linearizer RA.
Applied to the A/D conversion input terminal AN ₀ of the MCP. The linearizer RA is inserted to correct the nonlinearity caused by the self-heating of the thermistor NTC, but this is not always necessary. The microcomputer MCP has 2K bytes of ROM, 64 bytes of RAM, and a 2-channel A/D converter. The other A/D conversion input terminal AN ₁ of the microcomputer MCP has an AC power supply.
A pulsating voltage that is 100V stepped down by a transformer TR and full-wave rectified is applied, and the MCP detects the AC power supply voltage from this pulsating voltage. The MCP test terminal T ₀ has
Output pulses (timing pulses) from the encoder ENC, which generates pulses simultaneously with the rotation of the photoreceptor drum, are applied, and the MCP counts the pulses to determine control timing for each part. test terminal
A step-down alternating current is applied to _T1 , and the MCP detects its zero crossing point. The sensors in each part of the copying machine are connected to the AND/OR selector ARS for input port expansion, and are selectively activated according to the output commands X and Y.
Connected to input ports P _2-4 to P _2-7 of MCP.
Ports P ₀ and P ₁ of the MCP have a 2-digit 7-segment display 2 for copy number display, 3-digit 7-segment display 3 for temperature display, 2-digit 7-segment display 4 for heat-up time display, and 16 light emitting diodes. _GL to CP, etc. are connected, and these are dynamically displayed and activated by the MCP. _P0 is the scan pulse output end,
P ₁ is the segment drive end. The input/output expander IOE is connected to port _P2 of the MCP, and the key switches of the operation board are connected to _P3 of the input/output expander in a matrix. K ₀ to K ₉ are ten key switches for inputting numerical values. Ks is for copy start commands, K _I is for interrupt commands, Kc is for clear and stop commands, KM is for repeat copy (multi-copy) commands, and K _L and K _D are for dimming settings. While _KL is closed, MCP sequentially sets the brightness of the exposure lamp in the brighter direction, and in synchronization with this, shifts the light emission of light-emitting diodes _L1 to _L8 in the direction of _L1 → _L8 , and _KD The reverse setting is performed while the door is closed. Ports P ₄ ~ _{P 6} of input/output expander IOE
is used as the control output terminal for each element of the copying machine, and one of its terminals ``heat control A'' connects the solid state relay.
Triac conduction control pulse A is output to SSR. The terminal Ref of the MCP is used to set the upper temperature limit of the fixing heater 1, and can be set from Vcc/2 to Vcc. When detecting the temperature of fixing heater 1 between -20°C and 230°C, the range is 250°C, and MCP
has an 8-bit resolution, so 256 resolutions are possible. Equivalent to temperature change from -20℃ to 230℃
The low resistance change of NTC is input to AN ₀ as a change of 0 to 5V. In this case, the temperature measurement width and control accuracy are approximately 1°C. In hot roll fixing using fixing heater 1, the control point is approximately 200°C, so
After heat-up, the temperature is controlled at 1°C around 200°C, and the range is -20°C to 250°C.

The internal ROM of the microcomputer MCP contains
Control data for setting copying conditions, controlling various parts, and troubleshooting in response to key switch operations and detection signals from various sensors, as well as fusing heater temperature detection, A/D conversion, waiting time display, fusing heater energization control, Control data such as copy time calculation and display, as well as heat-up time data up to 200°C associated with fixing heater temperature T, are stored in memory.
In response to power-on, the various operations are performed based on the various control data.

Note that the heat-up time data up to 20°C associated with the fixing heater temperature T is when the heater 1 is energized in the energization mode (rated continuous energization up to 180°C, intermittent energization from 180°C) in the heater energization control described below. According to the temperature rise characteristic curve of the fixing heater 1, the temperature is changed from the temperature T at each point on the curve to 200
℃, and is extracted in advance based on the temperature rise characteristic curve of the fixing heater 1 and stored in the internal ROM of the MCP.

FIGS. 2a to 2c show control operations of the MCP, such as temperature detection, temperature display, heat-up time display, and heater control of the fixing heater. To explain these operations below, when the power is turned on in STEP-1, the MCP energizes heater 1 (STEP-1).
2). In other words, IOE's "Heater Control A"
, outputs a signal (continuous output) that instructs continuous energization of heater 1 (H, which instructs energization), and connects the solid state relay.
Give to SSR. The solid state relay SSR turns on in response to this signal and connects the heater 1 to the commercial AC power source. Next, the MCP performs A/D conversion of the temperature detection signal to obtain an initial value digital code (STEP-
3). That is, the voltage at the A/D conversion input port AN ₀ to which the detected temperature signal (analog voltage) of the thermistor NTC is applied is converted into a digital code. When the conversion is completed (STEP-4), the digital code is stored in accumulator register A (TEP-5), and the temperature value of heater 1 is calculated based on the digital code (STEP-6). Internal heat-up time from 200℃ to 200℃
The temperature value is read from the ROM (STEP-7) and the heat-up time is displayed on the display 3 and the heat-up time on the display 4 (STEP-8, 9). Immediately after the power is turned on, it has not heated up to 200°C, so a message indicating that copying is not possible is displayed (STEP-10).

Next, check whether the detected temperature T has reached 180℃ (STEP-11), jump to STEP-3 where it has not reached, and perform the above-mentioned temperature detection, heat-up time calculation, and temperature and time display (updating the display). will be carried out. In this way, the temperature detection signal of the thermistor NTC is repeatedly converted into digital data, the display is updated, and the detected temperature T of the thermistor NTC is
When the temperature reaches 180℃, switch to intermittent energization to suppress overshoot (STEP-12). i.e. IOE
A signal (pulse signal) instructing intermittent energization is output to the "heater control A" of the controller. Next A/
Digitally convert and read the voltage at the D conversion input terminal AN ₀ , and check whether the detected temperature T (temperature of heater 1) is 200°C (STEP-13). If the temperature has not reached 200℃, the device jumps to the above-mentioned STEP-3 with the intermittent energization setting, and performs digital conversion of the detected temperature and updating of the display.

More steps for microcomputer MCP
-2 to STEP-13, when the power is turned on, heater 1 is energized, and while the temperature detected by the thermistor NTC is 180℃, start from STEP-11.
Since the process returns to STEP-3, STEP-3 to STEP11 are repeatedly executed. That is, reading the temperature of heater 1 (STEP-3 to STEP-6), calculating the heat-up time (remaining waiting time) based on the read temperature (STEP-7), and displaying the character of the calculated remaining waiting time. The update display to 4 (STEP-9) is repeatedly executed. As a result, the display on the character display 4 shows the remaining waiting time calculated based on the actual temperature of the heater 1 at each point in time, and the first remaining waiting time calculation is performed after energizing the heater 1. Does not include temperature detection error or calculation error when When the temperature of heater 1 is above 180°C and below 200°C, energization of heater 1 is switched from continuous energization to intermittent energization to prevent heat-up overshoot (STEP-
12) However, temperature detection, waiting time calculation, and waiting time update display are repeatedly executed in the same way as when the temperature is below 180°C.

When the detected temperature T reaches 200°C, power to heater 1 is cut off (STEP-14), the detected temperature is digitally converted again and the display is updated (STEP-15~
STEP-19), Display copy permission (STEP-19)
9). After that, if the detected temperature T is between 200℃ and 205℃, it jumps to STEP-14 and T becomes 199℃.
If it is below, start energizing heater 1 and STEP-
Jump to 15. If T is 205° C. or higher, it is determined that the heater 1 is abnormal, and countermeasures are taken (STEP-26), and the copying machine is stopped. T is 195
If the temperature is below 0.degree. C. (STEP-23), it is determined that there is an abnormality and the process moves to a diagnostic routine (STEP-24).
In STEP-26, heater 1 is immediately shut off.
In other words, IOC's "Heater Control A"
Then, a signal L instructing to turn off the current is output.
In STEP-24, it is checked whether copying is possible, and if copying is not possible, it waits.

In this embodiment, three
Although a set of character displays 2, 3, and 4 are provided, they may be combined into one set. For example 4
When a set of digit 7-segment displays is used to display four types of information: number of copies, heater temperature, heat-up time, and required copy time, display these displays near the character display and use light-emitting diodes or lamps to display them. The instructions are given selectively, and the instructions for display contents and the display data are switched at intervals of one second or several seconds.
This can be done by measuring time using an internal counter or an external counter of the MCP, and setting program data to replace display latch data at predetermined intervals.

FIG. 3 shows a control flow for displaying the required copy time. In the display control of the copying time shown in FIG. 3, when displaying a set of displays for multiple purposes in a time-sharing manner as described above, the "time display"
In this step, the contents of the register that stores the required copy time data are updated, and at the timing assigned to display the required copy time, the data in the register is latched to the register that stores display data or the display data output port.

In the above embodiment, the heat-up time data corresponding to the heater temperature is stored in the ROM in advance, and the heat-up time data (waiting time data) corresponding to the heater temperature detected by the heat-up NTC is read from the ROM and displayed on the character display 4. However, a functional formula showing the relationship between the current temperature and the heat-up time is calculated in advance, and the calculation program data for calculating the heat-up time from the detected temperature is stored in the ROM. You may also ask for That is, fixing heater 1
According to the heater energization control described above, the required time for each temperature of the fusing heater to rise to 200°C is calculated based on the fixing temperature rise characteristics (NTC detection value) during energization, and the required time for the fusing heater temperature T is calculated. Obtain a graph or table showing time (heat-up time: t), define a function t=f(T) for the relationship between temperature T and time t, and substitute the data from the graph or table into this function. , for example, calculate the constant of the function using the method of least squares and identify the function,
An arithmetic program for calculating the heat-up time t corresponding to the detected temperature T by substituting the detected temperature T into this function and substituting the heat-up time T corresponding to the detected temperature T is stored in the ROM.

〔Effect of the invention〕

As described above, according to the present invention, the time data processing means MCP repeatedly reads temperature data (digital data) in time series, and the time required for the temperature of the fixing heater section indicated by the data to reach a predetermined fixing temperature, that is, Since data indicating the remaining waiting time is derived, it is possible to cope with the temperature rise of the fixing heater over time. The remaining waiting time corresponding to each momentary fixing heater temperature is repeatedly derived. Since the character display 4 updates and displays the time derived by the time data processing means MCP in numerical form, the time display on the character display 4 shows the remaining waiting time determined by the momentary temperature of the fixing heater section. It will be displayed.

Therefore, the operator can clearly know the remaining waiting time in years until the fixing heater reaches the fixing temperature. Therefore, the operator can effectively utilize the waiting time for other tasks, and is no longer irritated by waiting for copying.

For example, if the initial waiting time immediately after the power is turned on is calculated to be 5 minutes (300 seconds), and assuming that the error rate is 10%, there is an error within ±30 seconds for these 5 minutes. Assuming that these 5 minutes are the starting point, and then the elapsed time is subtracted from 5 minutes every second, and the remaining value is updated and displayed, the display will be displayed when the fusing heater temperature reaches the fixing temperature. is ±
It will be within the range of 30 seconds, and as time passes from the time when the initial value of the waiting time is calculated, the error rate of the displayed value with respect to the actual waiting time will increase, and the smaller the actual waiting time, the smaller the actual waiting time. This presents the problem of large table errors.

However, in the present invention, as described above, the temperature is read repeatedly in chronological order, and each time the temperature is read, the time required for the temperature to reach a predetermined fixing temperature is calculated, and this is updated and displayed on the character display 4. ,
Assuming that the error rate of time calculation is 10% as above,
When calculating the initial waiting time as 5 minutes, the display error at that time is within ±30 seconds, but for example, 30 seconds before the fusing heater temperature reaches the fixing temperature, the display error is within ±3 seconds, 20 seconds. Within ±2 seconds before, ± within 10 seconds before
Within 1 second..., and as the temperature approaches the fixing temperature, large display errors no longer occur.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the main parts of an embodiment of the present invention. Figures 2a, 2b and 2c
The figure shows the microcomputer MCP shown in Figure 1.
2 is a flowchart showing control operations for fixing temperature detection, temperature display, and heat-up time display. FIG. 3 is a flowchart showing the control operation of the microcomputer MCP shown in FIG. 1 for displaying the time required for copy processing. 1: Fixing heater (fixing heater), 2, 3: Character display, 4: Character display (Character display), SSR: Solid relay, NTC: Thermistor (temperature sensor), RA: Linearizer, TR: Transformer, ENC : Encoder, MCP: Microcomputer (A/D conversion means, time data processing means), ARS: AND/OR
Selector, IOE: Input/output port expander.

Claims (1)

[Scope of Claims] 1. A copying apparatus having a fixing heater, including: a temperature sensor that generates an electric signal corresponding to the temperature of the fixing heater section; an A/D conversion that converts the electric signal generated by the temperature sensor into digital data; means; repeating in chronological order to derive data indicating each time until the temperature of the fixing heater section at each point in time indicated by the digital data at each point converted by the A/D conversion means reaches a predetermined fixing temperature; , time data processing means; and, each time the time data processing means derives data indicating time, the time indicated by the derived data,
Character display updated in numerical form;
A copying device comprising: