JPS628183A - Fixing device - Google Patents

Abstract

PURPOSE:To prevent the temperature of a fixing roller from falling locally to cause a defect in fixation even during fast continuous copying operation by providing a heat source which heats both ends of a fixing roller with large heat radiation and driving forcibly the heat source which has power consumption less than specific power consumption even when the temperature of the fixing roller reaches a specific value. CONSTITUTION:An exposure lamp 11 and a main heater 3 are both driven to perform the exposure of an original unless temperature (t) reaches temperature (ts) when copying operation is started, and the exposure lamp 11 is turned off when the exposing operation is finished. Then, when the temperature (t) is held at the temperature (ts) continuously, the main heater 3 and an auxiliary heater 4 are turned off and when the temperature (t) does not reaches the temperature (ts), the main heater 3 and auxiliary heater 4 are both turned on. When the copying operation is all finished, next copying operation is started unless the set number of copies reaches zero, and this operation is repeated.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application This invention mainly relates to a hot roller type fixing device for a copying machine.

(b) Prior Art Generally, in this type of fixing device, a pair of rollers, at least one of which is heated, sandwiches and feeds a copy paper to heat and fix toner on the copy paper. However, if the heating temperature deviates from the predetermined fixing temperature range,
Temperature management of the fixing roller becomes a problem because the image quality of the toner on the copy paper deteriorates, the fixing rate decreases, and offset occurs when the toner adheres to the fixing roller.

Furthermore, since the most common commercial power source (plug-in power source) has a power capacity of 15 KVA (100 V, 15 A''), it is desirable that the blackout power of the copying machine be set to less than that.

The power consumption of a copying machine is mainly determined by the capacity of the heat source for fixing and the light source for exposure, so in order to effectively use the limited power for the heat source for fixing, it is necessary to make sure that the roller reaches a predetermined temperature as the heat source for fixing. For example, Japanese Patent Laid-Open No. 57/1999 discloses a fixing device including a main heat source that is driven when the roller is not operating, and an auxiliary heat source that is driven when the exposure light source is not driven when the roller does not reach a predetermined temperature.
-176078@) is proposed.

(C) Problems to be Solved by the Invention However, when copying operations are performed continuously at high speed, a large amount of heat is transferred to the copy paper. The amount of heat applied is insufficient, and the temperature at the center of the heating roll falls below a predetermined fixing temperature range. Furthermore, during warm-up or when copying is on standby, the temperature at both ends of the roller decreases due to heat radiation from the ends.
The temperature of the fixing roller is not uniform when copying starts. Therefore, it is difficult to uniformly control the temperature of the fixing roller, resulting in a problem of poor fixing.

The present invention was made in view of the above circumstances, and it is an object of the present invention to provide a fixing device that can supply heat m that enables good fixing while limiting the power consumption of a copying machine to a predetermined value. .

(d) Means to solve the problem FIG. 1 is a diagram showing the configuration of the present invention.

(101) is a fixing roller temperature detection means, (102) (
103) is a main heat source and an auxiliary heat source installed in the fixing roll, and (104) is a control circuit to which the output signal of the temperature detection means (101) and the exposure operation signal are input. The control circuit (104) detects the drive period of the exposure light source from the exposure operation signal, detects the temperature of the fixing roller at the start of the drive period using the temperature detection means (101), and compares it with a predetermined set value. If the roller temperature has not reached the set value, the main heat source (102) is forcibly driven, and if it has reached the set value, the auxiliary heat source (103) is forcibly driven during the driving period of the exposure light source. Roughly speaking, when a non-driving period of the exposure light source is detected from the exposure operation signal and the roller temperature has not reached the set temperature during that period, the main heat source (1
02) and the auxiliary heat source (103) are driven.

Further, it is desirable that the power consumption of the auxiliary heat source (103) is approximately equal to the power consumption of the exposure light source.

(e) Effect With this configuration, the auxiliary heat source (103) forcibly heats the roller even if the fixing roller reaches a predetermined temperature, so the amount of heat supplied to the fixing roller is increased compared to the conventional method. , the amount of heat absorbed by the copy paper is sufficiently replenished. Furthermore, when the exposure light source is not operating, that is, when warming up or when copying is on standby, the main heat source (102) heats the center of the roller, and the auxiliary heat source (103) heats both ends of the roller, so the temperature distribution of the roller is reduced. Uniform. Furthermore, since only either the auxiliary heat source or the main heat source is driven during the driving period of the exposure light source, the power consumption of the copying apparatus is suppressed within a predetermined value.

(f) Examples Hereinafter, the present invention will be described in detail based on examples shown in the drawings. Note that this invention is not limited to this.

FIG. 2 is a perspective view showing a fixing device according to an embodiment of the present invention, and (1a) shows a main heater (3) and an auxiliary heater (
(1b) is a fixing roller that is installed opposite to the fixing roller (1a) and rotates in the direction of the arrow to feed the copy paper (2J); (5) is a fixing roller that is equipped with This is a temperature detector that detects the temperature of the roller (1a).

FIG. 3 is a block diagram showing a control circuit of a copying machine equipped with this fixing device, and (6) shows RAM, ROM, CP
A microcomputer with a built-in U, (7)!j I
10. j<-t-, (8) U'la*D4'r@I″I
9! t-'f6tclI).

The start key (9) is the copy size specification key, (1
0) is the copy number setting key, αυ is the exposure lamp, [F] is the means of moving the exposure lamp 01), 03) is the exposure lamp (1)
1) is a driver that drives the main heater (3), 05] is a driver that drives the auxiliary heater (4), and (g) is a driver that drives the moving means az.

In this embodiment, a 300 W halogen lamp is used for the exposure lamp υ and the auxiliary heater (4), and a 900 W halogen lamp is used for the main heater (3).

The operation of such a configuration will be explained using the flowchart shown in FIG.

When the power of the copying machine is turned on (step 201), if the temperature (1) of the roller (1a) has not reached the predetermined set temperature (tS), the main heater (3) and the auxiliary heater (4) are turned on (step 202). are turned on at the same time (step 20
4) When the temperature +11 of the roller (1a) reaches a predetermined set temperature (tS), each heater (31 (4) is turned off (
Steps 202 and 203), copy size and number of copies are set by key (9) color (step 205)
).

Then, until the start key (8) is turned on, each heater (31 (4)) is repeatedly turned on and off (steps 202, 203, 204, 206), and the temperature (1) becomes the temperature (ts). Then, press the start key (8
) is turned on (step 20B), the copying operation is started (step 207), and the temperature of the roller (1a) (
1) has reached the set temperature (ts) (step 208), the exposure lamp pro υ and the auxiliary heater (4) are both driven to expose the document, and when the exposure operation is completed, the exposure lamp (11J) is activated. is turned off (step 211)
.

On the other hand, when the copying operation is started (step 207)
, if temperature (1) has not reached temperature ([S), then (
Step 208), exposure lamp (1υ) and main heater (3
) are driven together to expose the document, and when the exposure operation is completed, the exposure lamp (111) is turned off (step 211).Then, the temperature (1) is changed so that the temperature (1) is maintained at the temperature (ts). 1) has reached the temperature (ts) (step 212), the main heater (3) and the auxiliary heater (4) are turned off (step 213), and the temperature is 1 degree (ts).
1) has not reached the temperature (ts) (step 212), both the main heater (3) and the auxiliary heater (4) are turned on (step 214). When all the copying operations are completed (step 215), if the set number of copies is not zero (step 216), the next copying operation is started again (step 207), and then,
The above operation is repeated. If the number of copies has reached a predetermined number, the power is turned off and the process ends; otherwise, the process returns to step 202 to wait for the next copying operation.

In this way, during exposure, the roller (1a) is forcibly heated during the exposure period by the main heater (3) or the auxiliary heater (4), and during non-exposure, the roller (1a)
is maintained at the set temperature by the main and auxiliary heaters (31 (4)) and a large amount of heat is supplied, so the roller temperature does not drop due to lack of heat, and the temperature distribution is uniform to ensure good fusing. It will be done.

In addition, the power consumption of the heater and exposure lamp is 1200W.
It never exceeds.

Furthermore, the driving period of the exposure lamp depends on the temperature of the fixing roller (
Even if 1) changes, the driving state of the main heater or the auxiliary heater is maintained either on or off.

Therefore, the exposure lamp is prevented from flickering due to fluctuations in the power supply voltage as the heater is turned on and off.

(G) Effects of the Invention According to the present invention, a heat source is provided that heats both ends of the fixing roller that radiates a large amount of heat, and even when the temperature of the fixing roller reaches a predetermined value, the power consumption is kept within the predetermined power consumption. Since the heat source is forcibly driven, the amount of heat supplied to the fixing roller is increased, and even during high-speed continuous copying, the temperature of the fixing roller does not drop locally and cause fixing failure. A fusing device is provided.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the configuration of the present invention, FIG. 2 is a perspective view showing an embodiment of the invention, FIG. 3 is a block diagram showing a copying apparatus to which an embodiment of the invention is applied, and FIG. The figure is the third
3 is a flowchart showing the operation of the figure. (1a) (1b)...Fixing roller, ('2
J... Copy paper, (3)... Main heater,
(4)... Auxiliary heater, (5)...
Temperature detector, (6) Microcomputer, +tU Exposure lamp procedure correction layer August 1985 Relationship between the name fixing device 3 and the case of the person making the amendment Patent applicant address 1-2-28 Tamatsukuri, Higashi-ku, Osaka Name
(615) Mita Kogyo Co., Ltd. Representative Junki Mita 4, Agent 530 Address 1-3 Quarter, Nishitenma 5-chome, Kita-ku, Osaka
One Bill 5, Date of amendment order Initial issue 6, Subject of amendment 7, Contents of amendment (1) "Claims" column As shown in the appendix (2J "Detailed description of the invention" column 1, Specification No. 4 In the 6th line of the page, ``(103) is the master set in each fixing roll'' is r <103>
is set within the fixing roll and increases the amount of heat generated at approximately the center and approximately at both ends of the fixing roll. 2. Same page - "Drive" in lines 10 and 15 of the same page
3. Correct "when operating" on page 5, line 9 of the same page to "when lit". 4. Correct "ga roller" in lines 10 and 11 of page 5 of the same book to "r mainly means roller." 5. Correct "driving" to "lighting" in line 113 of the same page on the same layer. 6. r (la) in the 1st and 2nd lines of page 6 of the same book is the fixing roller with the main heater (3) and the auxiliary heater (4) installed inside. 4) has been corrected to ``main heater and auxiliary heater that increase the amount of heat generated at approximately the center and approximately both ends of the fixing roller (1a). 7. Same mouth, same page, line 13, ``Correct drive j to ``light up''. 8. Correct "drive" in page 7, line 18 of the same book, page 8, line 4 of the same book, and page 9, line 9 of the same book, to read "r on." 9. In the same book, page 9, line 16, "provide a heat source that heats both ends" is corrected to "provide an additional heat source that mainly heats both ends."Claim 1: A light source for exposing the original In a fixing device of a copying machine that exposes to light and makes copies, a main heat source and an auxiliary heat source installed in the fixing roller and located at approximately the center and approximately both ends of the fixing roller, respectively, increase the amount, and the temperature of the fixing roller. and a control circuit that drives and controls these heat sources, and the control circuit is configured to control the LL of the exposure light source when it is movable.
At the start, when the roller temperature has reached a predetermined set temperature, the auxiliary heat source is forcibly driven, and when the roller temperature has not reached the predetermined set temperature, the main heat source is forcibly driven during the m period of the exposure light source, and the auxiliary heat source is forcibly driven during the m period of the exposure light source. The fixing device is configured to drive the main heat source and the auxiliary heat source when the roller temperature does not reach a set temperature. 2. The fixing device according to claim 1, wherein the power consumption of the auxiliary heat source is approximately equal to the power consumption of the exposure light source.

Claims (1)

[Scope of Claims] 1. In a fixing device of a copying machine that exposes a document to an exposure light source and copies it, a main heat source installed inside the fixing roller and heating substantially the center and substantially both ends of the fixing roller, respectively. and an auxiliary heat source;
The fixing roller includes temperature detection means for detecting the temperature of the fixing roller, and a control circuit for driving and controlling those heat sources, and the control circuit detects when the roller temperature reaches a predetermined set temperature when the exposure light source starts to be driven. auxiliary heat source,
When the roller temperature does not reach the set temperature, the main heat source is forcibly driven during the driving period of the exposure light source, and when the roller temperature does not reach the set temperature during the non-driving period of the exposure light source, the main heat source and the auxiliary heat source are driven. A fixing device characterized by being configured as follows. 2. The fixing device according to claim 1, wherein the power consumption of the auxiliary heat source is approximately equal to the power consumption of the exposure light source.