JPS6195379A - Fixing device - Google Patents

Abstract

PURPOSE:To provide a good fixing characteristic by having a control means for subjecting the electric power to be impressed to a heating means to phase control in accordance with the size signal from means for detecting the size of copying paper which detect the size of the copying paper to be supplied to a fixing device. CONSTITUTION:The copying paper size signals from the means 66, 67 for detecting the size of the copying paper are impressed to a microcomputer 68 as means for control, discrimination and change and the phase control signal from the microcomputer 68 is impressed to a phase control circuit 63. The stable signal from the circuit 63 is impressed to the microcomputer 68. A commercial AC voltage is impressed to the circuit 63 which impresses the commercial AC voltage subjected to the phase control in accordance with the phase control signal to the roller heating means 65. The temp. detection signal from a temp. detecting means 64 is impressed to the circuit 63.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field> The present invention relates to a fixing device, and more specifically, the present invention relates to a fixing device, and more specifically, heats at least one of a pair of rollers, and uses the pair of rollers to sandwich a copy sheet after a toner image has been transferred thereto. The present invention relates to a constant @v device that fixes a toner image on copy paper while conveying it under pressure.

<Prior art> Conventionally, there are copying machines that control the fuser heater. ■ The power applied to the fuser heater must be controlled so that the power consumption of the entire copying machine does not exceed the rated value when the light source for exposing the original is turned on. A fixing device that controls the phase of electric power, ■ A fixing device that installs heaters of multiple seconds corresponding to the size of the copy paper and controls the power applied to each heater by detecting the size of the copy paper (Japanese Patent Laid-Open No. 57-63570 (Refer to the publication), ■ A fusing device that controls the fusing temperature according to the size of the copy paper! ¥ (Refer to Japanese Unexamined Patent Publication No. 56-72470)
There is.

However, the fixing device with the above configuration (■) is simply designed to prevent the power consumption of the entire copying machine from exceeding the rated value, so no consideration is given to the size of the copy paper, and it simply turns on the light source. At times, the power applied to the fixing heater is reduced, and when the light source is not lit, the power applied to the fixing heater is increased. Therefore, there is a problem that the fixing characteristics cannot be kept constant.

The fixing device with the above configuration (■) can control the fixing heater according to the size of the copy paper, but the number of fixing heaters is large;
Not only does this complicate the configuration, but it also complicates IIJIIl since it is necessary to apply electric power tsm to each fixing heater.Furthermore, the temperature of the fixing roller is controlled step by step depending on the position. It is necessary to set each of them to a slightly higher value, which has the disadvantage of wasting heat and power.

In addition, the fixing device configured as described in (2) above has a fixed size that corresponds to the size of the copy paper. ! There are things that change the knitting pattern [because there is a temporary odor] in order to exhibit good fixing characteristics during continuous copying.
It is necessary to set the temperature to a considerably nth value, which is disadvantageous in that it wastes energy, heat, and power.

<Purpose> This invention was made in view of the above problems.
The power applied to the fixing roller is controlled according to the size of the copy paper, and good fixing characteristics are achieved even when copying large numbers of sheets in succession using large size copy paper. It is an object of the present invention to provide a fixing device that can reduce heat and power consumption and reduce waste of heat and power.

Configuration> To achieve the above object, the fixing device of the present invention has the following features:
The copy paper 1 noise detection means and the 1ill1 means are installed in the copy paper transport path, and the copy paper size detection means detects the size □ of the copy paper supplied to the fixing device. The photoelectric element J''aa is detected by a reed switch, etc. for determining the type of paper feed cassette attached to the fixed position for copying, and outputs a copy paper size signal.
The IW means is for controlling the phase of the power applied to the roller heating means consisting of a heater etc. based on the copy paper size signal, and uses a phase control signal that is preset according to the copy paper size signal. The phase control may be performed by reading out the phase 1. Phase control may be performed by obtaining the II control signal. Therefore, the heat I11 taken away from the fixing device differs depending on the size of the copy paper, but without setting the temperature to a high temperature in advance according to the size of the copy paper, the amount of heat corresponding to the heat m taken away is determined by the roller heating means. It is possible to reduce waste of heat and power consumption by 1111 points.

However, in the above case, the temperature of the -C1 fixing device is detected by a 4 degree detection means such as a thermistor, and due to variations in paper quality, etc., the temperature of the fixing device is kept constant in the phase tsm by the phase 1.13 control signal. If the structure is changed to determine when it cannot be maintained and change the phase IIJtIIl signal, the amount of heat,
This is preferable because it further suppresses wastage of power consumption. Regarding changes to the phase control signal, it is possible to increase or decrease it by a predetermined amount, or to increase or decrease it based on m degrees after a predetermined period of time has elapsed.
It is.

<Example> Hereinafter, embodiments will be described in detail with reference to the accompanying drawings showing examples.

FIG. 4 is a schematic diagram clearly showing the internal structure of the copying machine of the present invention.

(1) is the main body of the copying machine, and the division plate (11)
The interior is divided into an upper chamber (12) and a lower chamber (13),
: An optical section (2) for scanning and exposing the original is provided in the room (12), and a copy processing section (4) for forming a copy image on copy paper (P) and a copy processing section (4) in the lower part (13). Paper transport section (
5) is provided.

Here, the optical part (2) includes a light emitter (31), a main anti-copper plate (32), and (j 1IF1 anti(144k (33
) teli4 成'c;t'tle"/l m(21
), plane reflector (22) (23024), lens (25
), and has a flat anti-rJ4 mirror (26) and a guide shaft (
27) Scan the original on the contact glass (14) by moving the light source (21) and flat reflector (22) (23) (24) in the direction shown by arrow A along (28). The structure allows exposure. Then, the light source (2
1), and the plane reflecting mirror (22) move into one unit, and the plane reflection It (23) and (24) also move into one unit, and the moving speed of the former is set to be twice the moving speed of the latter. has been done. In addition, the copy paper transport unit (9 includes paper feed rollers (51) (52), paper feed paths (53) (54), registration rollers (55a), transport rollers (56), transport belt (57), fixing Heat fixing O-ra (58) as a device,
J3 and a discharge roller (59), and by selectively driving one of the paper feed rollers, a single-sheet copy paper (P) can be taken out from either one of the paper feed cassettes (16) or (17). , the copy processing unit (4) transfers the toner image, the heat fixing roller (58) heats the toner image,
There is a configuration C in which the paper is ejected onto the pedestal (18) after it is fixed, but B and e are not limited to this configuration; for example, there is a configuration in which the paper feed side and the ejection side are on the same side. It is also possible to use a copy paper conveying section having another structure that is conventionally known. Furthermore, near the mounting position of the paper feed cassette (16017) on the main body of the copying machine, a copy paper size detection means (6
6) (67) are installed, and paper feed cassettes (16) (1
1) Magnet attached to the specified position! - Copy paper size signal by being driven by (not shown).

can be output. The copy processing unit G4) includes a photosensitive drum (41) that rotates in the direction shown by C in the figure.
There is a charger (42) and a blank lamp (B
), developing device (43), transfer charger (44), separation charger (45), and cleaner (46).

The blank lamp (B) removes the static charge on the outer peripheral edge of the photoreceptor drum (41), which is arranged in this order and is uniformly charged by the charger (42). - to form an electrostatic latent image, the developing device 1 (43) develops the toner image into a toner image, and the transfer charger (44) transfers the toner image to the copy paper (P).
Although the configuration is such that the residual toner is transferred onto the surface and collected by a cleaner (46), the configuration is not limited to this configuration. It is possible to use a copy processing section having the following configuration.

FIG. 1 is a perspective view of the heat fixing roller (58), which includes a heat roller (61) with a roller heating means (65) such as a heater installed inside, and a pressure roller that rotates in pressure contact with the heat roller (61). (62) and a phase control circuit (65) as a control means.
3) Apply commercial AC voltage via (see Figure 2)
At the same time, a temperature detection means (64) consisting of a thermistor or the like is installed in close proximity to a predetermined position of the heating roller (61).

FIG. 2 is a block diagram for controlling the power applied to the roller heating means (65), and includes the CPU, RAM, and ROM.
.

[Control means having 10 ports, clock generator, etc.;
The microcomputer (
68), a copy paper size signal from the copy paper size detection means (6G) (67) is applied, and a phase control signal from the microcomputer (68) is applied to the phase control circuit (63). . Then, the phase control circuit (6
3) Stable signal from microphone ``'' computer (68)
is applied to. Further, the phase control 1 circuit (63) applies a commercial AC voltage to the roller heating means (65), which is a commercial AC voltage whose phase is controlled in accordance with the lflL! phase control signal. Then, the temperature detection means (
A temperature detection signal from the phase control circuit (64) is applied to the phase control circuit (63). Note that (69) is an external memory in which a phase control signal corresponding to the copy paper size is stored in advance.

FIG. 3 is a flowchart showing the operation of the fixing device configured as described above.

If you turn on the power switch (not shown) on the copying machine,
Step ■ Smell ° [10
Apply a commercial AC voltage with a 0% energization rate to the heating roller (
61) is rapidly heated up in u1 step ■ WAr!
The temperature detection signal from the first detection means (64) is applied to the phase control circuit (63), and the phase control circuit (63) is output when the detected temperature is within a predetermined range e set in advance.
The stable signal from 63) is sent to the microcomputer (68).
The fixing device! It is determined whether or not (58) is stable. Then, C continues to energize the cola heating means (65) until the set temperature is reached.

On the other hand, when the fixing device FF (5B) is stabilized, the copy paper size signal from the copy paper size detection means (6B) (67) is read in step (2), and the 16-position phase control ( , ? are read from the external memory (69), and in step (2), the read out phase control ll signal is applied to the phase control circuit (63), so that in step (2), the energization rate is set at a predetermined energization rate determined by the phase 1iIJIj signal. , roller heating means (65
) with a commercial AC mill. That is, the roller heating means (
65) can be optimally set according to the copy paper size.

After that, it is determined whether the fixing device (58) is stable or not in step (2), and if it is determined that it is not stable, the microcomputer (58) is checked in step (2).
It is determined whether the timer included in step 68) is in operation, and if the timer is already in operation, it is determined in step (■) whether the time measured by the timer has elapsed and the timer is not activated. For example, after starting the clocking operation by the C timer in step [phase], the determination of step 0 is performed.

Then, in step ■ (if it is determined that the timer has not passed the 11 o'clock time and it is IC, the determination and processing below in step ■ is performed; on the other hand, if it is determined that the time measured has elapsed, in step @) After changing the phase control signal, perform the determination and processing following step (2).

If it is determined in step (2) that the C fixing device FF (58) is stable, the timer is cleared in step (2), and the determination of snap (2) is made again.

In summary, at the beginning of the operation of the copying machine, by applying a commercial AC voltage to the roller heating means (65) at 100% energization rate, the temperature is rapidly raised to the set density that is considered optimal for the fixing operation. After that, a commercial AC voltage is applied to the roller heating means (65) at a energization rate corresponding to the size of the copy paper selected by the copy paper selection means (not shown). The heat fil, 1
It is possible to significantly suppress waste of m-cost electric power.

However, at the energization rate corresponding to the selected copy paper size.
Even if a commercial AC voltage is applied to the roller heating means (65), the temperature of the fixing device (58) may not be stable depending on the ambient temperature, the thickness of the copy paper, etc.; Since the energization rate is changed by changing the 17 phase control signal when the temperature of the fixing device [(5B) is not stable, waste of heat m, n\1j power can be significantly suppressed. .

Note that in step 4 above, the phase control signal may be unconditionally changed to one corresponding to the one size larger copy paper, but if the fixing device (58) is not stable, the actual By determining whether the hot stone is n or lower than the set m degree, the phase IIJgIl signal corresponding to the one size larger copy paper size or the phase l + control signal one size smaller is selected and changed to the selected phase mil control signal. If there is something C to do, it would be preferable because appropriate measures would be taken that are appropriate to the current situation. In addition, when the fixing device (58) is not stable, the temperature difference between the actual temperature and the set temperature is obtained, and the C phase control signal can be changed based on this temperature difference. If so, it would be possible to take measures more appropriate to the current situation, which would be even more preferable.

Note that the present invention is not limited to the above-mentioned actual/ll8il; for example, the external memory (69) may be omitted and the internal memory of the microcomputer (68) may be used, or the temperature detection means (64) may be used. ! A copy paper size detector stage '□ consisting of a photoelectric element or the like is installed at a predetermined position of the copy paper conveying section (5) by directly applying a feed detection signal to the microcomputer (68) to determine whether or not it is in a stable state. It is also possible to make various changes to the installation J1 without changing the gist of the invention.

Effects> As described above, the present invention is capable of changing the power applied to the heating means by phase control in accordance with the size of the copy paper. death〔
Compared to the conventional example in which the set S mark is changed, the unique effects of reducing waste of heat and power consumption and maintaining good fixing performance are achieved.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the fixing device, FIG. 2 is a block diagram, FIG. 3 is a flowchart, and FIG. 4 is a schematic diagram showing the internal mechanism of the copying machine. (58) ... Heat fixing 0-ra of C as a fixing device, (6
1)...heating roller, (62)-ftl'trl-ra, (63)...phase u control circuit as control means, (
64)... Onmaro detection means, (65)... Roller heating means, (66) (67)... Copy paper size detection means,
(68)...Microcomputer as control means, discrimination means, and change means [Fig. 2]

Claims (1)

[Claims] 1. A pair of rollers, at least one of which is heated , the toner image grips the copy paper after transfer, By conveying the toner image to the copy paper In the fixing device that fixes the detects the size of copy paper fed to the machine. Copy paper size detection means and copy paper size detection means based on the copy paper size signal from the size detection means. to phase the power applied to the roller heating means. and a control means for controlling Fixing device. 2. Temperature detection means for detecting the temperature of the roller and the position corresponding to the copy paper size signal. Check whether the temperature has been stabilized by phase control. It has a discriminating means to determine whether the temperature is stable or not. Modification to change the phase control signal if it is not present The above claim having the means The fixing device according to item 1. 3. Phase control corresponding to copy paper size signal The above patent claim in which the signal is preset The fixing device described in item 1 or 2 of the scope of Place.