JPH1138828A - Printing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printing device capable of continuing the printing while maintaining a given fixing performance, even in a state of occurrence of failure in a part of heaters among a plurality of numbers of heaters. SOLUTION: In this printing device provided with a fixing unit equipped with plural rolls of heaters 104 and 105 with different light orientational distribution in the lengthwise direction, the device is provided with heater failure detecting means 115 and 116 independently outputting a signal of detecting the failure with regard to respective plural rolls of heaters 104 and 105, printing possibility deciding means 118 deciding whether printing is possible or not on the occurrence of failure on a part of heaters based on the detecting signal input from the heater failure detecting means 115 and 116, and printing controlling means 111 being set so as to continue the printing by the printing control being different from the case when every heater is normal so as to maintain the excellent fixing performance when judged that the printing is possible by printing possibility judging means 118, while being set so as to stop the printing when judged that the printing is impossible.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus (printer) provided with a fixing device having a plurality of heaters having different light distributions in a longitudinal direction.

[0002]

2. Description of the Related Art In a fixing device of a printing apparatus of this kind, it is important how to deal with a failure of a heater.

[0003] As one of the conventional handling methods, there is known a method in which printing is immediately stopped when at least one of a plurality of heaters fails.

[0004] This means that printing is stopped at all, even though some heating is possible with the remaining heaters. However, some users desire to be able to continue printing even if the fixing performance is slightly reduced. In particular, it can be said that it is very inconvenient that printing cannot be performed at all until the repair is performed by a serviceman.

[0005] On the other hand, as another conventional example, there is also known one in which a printing operation under normal control is continued by using a part of the remaining heaters unless all the heaters fail.

[0006]

However, if the printing operation is continued under normal control with some of the remaining heaters as described above, the temperature distribution in the longitudinal direction of the fixing roller will be deviated, and a predetermined fixing will occur. There is a possibility that printing may be performed without maintaining the properties.

An object of the present invention is to solve the problems of the conventional example,
It is an object of the present invention to provide a printing apparatus capable of continuing printing while maintaining a predetermined fixing property even when some of the plurality of heaters have failed.

[0008]

According to a first aspect of the present invention, there is provided a printing apparatus provided with a fixing device having a plurality of heaters having different light distributions in a longitudinal direction. Heater failure detection means for independently outputting a signal for detecting a failure for each of the heaters; and whether or not printing is possible when some of the heaters fail based on the detection signal input from the heater failure detection means. Printability judging means for judging the printability, and printing is continued by a print control different from that in the case where all heaters are normal so that good fixability is maintained when the printability judgment means judges that printing is possible. On the other hand, this is achieved by providing a print control means which is set to stop printing when it is determined that printing is impossible.

According to the second aspect of the present invention,
An object of the present invention is to provide a print control device according to the first invention, wherein when it is determined that printing is possible when some of the heaters fail, the heater temperature control is performed so as to correct the deviation of the light distribution of the remaining heaters. Is achieved by being set to perform.

[0010] According to a third aspect of the present invention,
The above object is achieved by that the printing control means of the second invention is set so as to forcibly increase the printing paper interval when it is determined that printing is possible when some heaters fail. Is done.

According to a fourth aspect of the present invention,
The object of the present invention is to determine the printability by adding the type of paper to be printed together with the normal heater remaining when some of the heaters have failed, to the printability determining means of the first invention. This is achieved by being set as follows.

According to a fifth aspect of the present invention,
In the first invention, there is provided state management means for continuing the printable state while issuing a warning of the occurrence of a heater abnormality when the printability determination means determines that printing is possible when some of the heaters fail. Is achieved.

That is, in the first invention according to the present application, when the printability determining means determines that printing is possible when some of the plurality of heaters fail, the print control means sets The printing control is different from the case where all the heaters are normal. That is, even when some of the heaters fail, printing is continued while maintaining the predetermined fixing property.

Further, in the second invention according to the present application, the printing control means of the first invention controls the temperature of the heater so as to reduce the deviation of the light distribution of the remaining normal heater. Do. Therefore, even if some of the heaters fail, printing is continued while maintaining the predetermined fixability.

Further, in the third invention according to the present application, the print control means of the second invention forcibly increases the paper interval for printing, so that the heat of the fixing roller is reduced. The temperature distribution over the entire area of the fixing roller is made uniform until the next sheet is fixed. Therefore, even if some heaters fail during continuous fixing,
Printing is continued while maintaining the predetermined fixing property.

Further, in the fourth invention according to the present application, the printability determining means of the first invention adds the type of the paper to be printed to the determination condition together with the remaining normal heater. , To determine the printability. In other words, by limiting the type of paper to be printed at the stage of determining printability,
Even if some of the heaters fail, printing is continued while maintaining the fixability.

Further, in the fifth invention according to the present application, in the first invention, even when some of the heaters are out of order, the state management means issues a warning of the occurrence of a heater abnormality while the heater is operating. Continue printing. In other words, before all the heaters fail and printing becomes completely impossible, a warning is issued to the outside even if only some of the heaters fail.

[0018]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

(First Embodiment) A first embodiment of the present invention will be described with reference to FIGS.

FIG. 2 shows the entirety of a laser beam printer 201 which is a printing apparatus according to this embodiment.

The laser beam printer 201 includes a cassette 203 for storing paper 202, a multi-purpose tray 207 for manually feeding irregular-sized paper, and a laser scanner 212 disposed downstream of the cassette 203 and the multi-purpose tray 207. Image forming section 211 for forming an image with the laser light
And a fixing device 213 disposed downstream of the fixing device 213.
And a paper discharge unit 219 disposed downstream of the printer.

Paper is supplied from the cassette 203 or the multi-purpose tray 207, and the image forming unit 2
After the printing at 11, the image is fixed by heating and pressurizing at a fixing unit 213, and then discharged to a paper discharge unit 219.

Here, the fixing device 213 is shown in FIG.

The fixing device 213 includes a fixing roller 90 having heaters 104 and 105 therein, a pressure roller 91 for pressing a sheet against the fixing roller 90, and a thermistor 103 as a temperature sensor for detecting the surface temperature of the fixing roller 90. have. The fixing device 213 is configured such that the engine main control circuit 101 controls the heater 1 based on the temperature detection of the thermistor 103.
04 and 105 are controlled.

In this embodiment, the fixing roller 90 has two heaters 104 and 105 having different light distributions in the longitudinal direction. One is a main heater 104 and the other is a sub-heater 105. Main heater 104
Has a light distribution near the center in the longitudinal direction of the fixing roller 90 (see FIG. 3B). The sub-heater 105 has a light distribution near both ends of the fixing roller 90 (FIG. 3).
(C)).

Since the thermistor 103 is provided in contact with the fixing roller 90, it is arranged at the end of the fixing roller 90 where the sheet does not pass.

FIG. 1 shows a control circuit according to this embodiment.

The laser beam printer 2 shown in FIG.
01 is an engine main control unit 10 for controlling the entire engine.
One. In the engine main control unit 101, the thermistor 103 is connected via a temperature detection circuit 106,
The main heater 104 is connected via a main heater drive circuit 107, the sub-heater 105 is connected via a sub-heater drive circuit 108, and the cassette paper size detecting means 1
09 is connected, and the external device 102 is connected.

The main heater drive circuit 107 and the sub-heater drive circuit 108 supply electricity to the main heater 104 and the sub-heater 105 in accordance with an instruction from the heater drive control means 112 in the engine main controller 101. The main heater driving circuit 107 and the sub-heater driving circuit 108 additionally have a main heater 1
04, a circuit for detecting the energization state of the sub-heater 105 is provided. If the energization cannot be performed normally despite the fact that the heaters 104 and 105 are to be driven, a signal indicating a heater abnormality is output. ing. This configuration is well known and will not be described in detail.

The engine main control unit 101 includes therein a state management unit 110, a print control unit 111, a heater drive control unit 112, an external device communication unit 113, a paper size information storage unit 114, and a main heater failure unit. Detection means 1
15, a sub-heater failure detection unit 116, a temperature comparison value storage unit 117, and a printability determination unit 118.

Here, the state management means 110 manages control states of the laser beam printer 201 such as warm-up, standby, printing, and failure. Particularly, in the present embodiment, the state management unit 11
0 indicates that when the printability determining means 118 determines that printing is impossible, it determines that a failure has occurred, and notifies the external device 102 that it is in a failure state.

The print control unit 111 is connected to the external device 1.
The printing instruction is received from the external device communication means 113 via the external device communication means 113, and the respective parts of the laser beam printer 201 are controlled in accordance with a known electrophotographic process to control the printing operation. In particular, in the present embodiment, the print management unit 111 determines that printing is possible even when some of the heaters fail.

In addition, the heater drive control means 112 controls the main heater 10 in accordance with an instruction from the print control means 111.
4. To control the temperature of the fixing device 213 by controlling the sub-heater 105. That is, the heater drive control unit 112 controls the fixing roller 90 from the thermistor 103.
And the temperature of the heaters 104 and 105 is controlled so that the temperature of the fixing roller 90 becomes equal to the temperature comparison value stored in the temperature comparison value storage means 117.

The external device communication means 113 controls communication with the external device 102 via an interface.

The paper size information storage means 114 stores information on the paper size of the cassette 203 from the cassette paper size detection means 109 and the multi-purpose data designated by the external equipment 102 and transmitted via the external equipment communication means 113. The information on the paper size of the tray 207 is stored.

The main heater failure detection means 115 and the sub-heater failure detection means 116 monitor the heater abnormality signals output from the main heater drive circuit 107 and the sub-heater drive circuit 108, respectively, and detect the failure of the main heater 104 and the sub-heater 105, respectively. Is to be detected.

The temperature comparison value storage means 117 receives and stores the target temperatures (temperature comparison values) of the heaters 104 and 105 from the print control means 111, and stores them.
The stored temperature comparison value is output to the heater drive control means 112.

The printability determining means 118 determines whether printing is possible based on information from the main heater failure detection means 115 and the sub-heater failure detection means 116.

The printing possibility determining means 118 of this embodiment
Determines that printing is not possible only when a failure is detected in both the main heater 104 and the sub-heater 105.
If it is determined that printing is not possible, printability determining means 118
Reports that printing is not possible to the state management means 110. Upon receiving the information indicating that printing is impossible, the state management unit 110 determines that the laser beam printer 201 is in a failure state, instructs the print control unit 111 to stop the printing operation, and outputs the external device 102 via the external device communication unit 113. Output failure information.

On the other hand, the printing possibility determination means 118 is set so that printing is continued when only one of the main heater 104 and the sub-heater 105 fails. At this time, if normal print control, that is, print control similar to the case where both heaters 104 and 105 are normal is performed, a fixing failure may occur. This is because only one of the heaters is normal, and the light distribution is deviated. Therefore, the print control unit 111 according to the present embodiment determines whether both the heaters 104 and 105 are normal, if only the sub-heater 105 is normal,
When only the main heater 104 is normal, the fixing temperature is controlled so as to change the control target value as follows.

When both the heaters 104 and 105 are normal, the print control unit 111 sets a normal control target value as the temperature comparison value of the thermistor 103 in the temperature comparison value unit 117. The normal control target value is a value that is set as a control target for each printing condition determined in advance.

When only the sub-heater 105 is normal, the print control unit 111 sets the temperature comparison value of the thermistor 103 in the temperature comparison value unit 117 to be higher than the normal control target value. The reason for setting higher is that thermistor 10
3 is located on the end side of the fixing roller 90, and the light distribution is normal only for the sub-heater 105 offset to the end side of the fixing roller 90. Therefore, the temperature near the center of the fixing roller 90 in the longitudinal direction becomes thermistor 103. This is because the temperature becomes lower than the detected temperature. The degree of increasing the temperature comparison value is
An optimum value obtained in advance by an experiment or the like is used.

When Only the Main Heater 104 is Normal The print control unit 111 sets the temperature comparison value of the thermistor 103 in the temperature comparison value unit 117 to be lower than the normal control target value. The reason for setting the temperature lower is that the position of the thermistor 103 is on the end face side of the fixing roller 90 and the light distribution is normal only in the main heater 104 which is biased toward the center of the fixing roller 90 in the longitudinal direction. This is because the temperature near the center in the direction becomes higher than the temperature detected by the thermistor 103. As the degree to which the temperature comparison value is lowered, an optimum value obtained in advance by an experiment or the like is used.

By controlling the temperature of the fixing device as described above, even if only one of the heaters fails, the deviation of the light distribution in the longitudinal direction of the fixing roller 90 can be corrected, and good fixing can be achieved. Printing is to be continued while maintaining the performance.

According to the printer having the above-described configuration according to the present embodiment, as described below, printing is continued while correcting the deviation of the light distribution in the longitudinal direction of the fixing roller 90 and maintaining good fixing performance. .

The fixing temperature control will be described mainly with reference to the flowchart of FIG.

First, the possibility judging means 118 checks whether or not the main heater 104 is normal in step S001, and proceeds to step S002 if the main heater 104 is normal. Further, in step S002, it is checked whether or not the sub-heater 105 is normal, and if it is normal, the process proceeds to step S003. As described above, when both the heaters 104 and 105 are normal, the print control unit 111 sets the set value of the temperature comparison value 117 of the thermistor 103 to a normal control target value in step S003.

In step S001, the main heater 1
If the sub-heater 105 is normal in step S004 even if the 04 is faulty, the process proceeds to step S005, where the print control unit 111 sets the temperature comparison value of the thermistor 103 set in the temperature comparison value unit 117 to the normal control target. Set higher than the value. The reason for setting a higher value is that the position of the thermistor 103 is on the end side of the fixing roller 90, and the light distribution is offset to the end side of the fixing roller 90.
This is because the temperature near the center of the fixing roller 90 in the longitudinal direction becomes lower than the temperature detected by the thermistor 103 because only 5 is normal.

In step S001, the main heater 1
04 is normal, and the sub-heater 10
If a failure is detected in Step 5, the process proceeds to Step S006, and the print control unit 111 sets the value of the temperature comparison value set in the temperature comparison value unit 117 to be lower than the normal control target value. The reason for setting the temperature lower is that the position of the thermistor 103 is on the end side of the fixing roller 90 and the light distribution is shifted to the center of the fixing roller 90 in the longitudinal direction.
This is because the temperature near the center of the fixing roller 90 in the longitudinal direction becomes higher than the temperature detected by the thermistor 103 because only the reference numeral 05 is normal.

In step S001, the main heater 1
If the sub-heater 04 has failed and the sub-heater 105 has failed in step S004,
Judge that printing is not possible. Based on this determination that printing is not possible, the state management means 110
Are in a failure state, the print control unit 111 stops the print control, and outputs failure information to the external device 102 via the external device communication unit 113.

As described above, when only one of the heaters 104 and 105 fails, the temperature comparison value of the thermistor 103 is set to be higher or lower than the normal control target value so that the longitudinal direction of the fixing roller 90 can be reduced. Of the light distribution is corrected, and printing is continued while maintaining good fixability.

In the present embodiment, the number of heaters is two, and when one of the heaters fails, the printability determining means 118 determines that there is printability. However, the present invention is not limited to this.
The number of heaters may be a plurality, and the presence / absence of printing possibility may be appropriately determined from the number of remaining normal heaters and the light distribution.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIGS. 1 and 2 and the flowchart of FIG. In this embodiment, the configuration of the laser beam printer is the same as that of FIG. 2, the control circuit configuration is the same as that of FIG. 1, and only the control content of the print control unit 111 is different.

In the above-described first embodiment, when one of the heaters fails, the temperature control of the heater is changed to cope with the failure. On the other hand, in the second embodiment, the fixing roller 90
In addition to the light distribution distribution correction, the interval between printing papers is forcibly provided.

In the case of simply changing the temperature control of the heater, for example, when the main heater 104 fails, if a plurality of sheets are continuously printed, the sheets take away the heat of the fixing roller 90 and the center of the fixing roller 90 is removed. The temperature in the vicinity gradually decreases. Also, when only the sub-heater 105 fails, the temperature near the end of the fixing roller 90 decreases. That is, even if the temperature control of the heater is changed,
In the case of continuous fixing, the temperature distribution in the longitudinal direction of the fixing roller 90 becomes non-uniform. Therefore, in the present embodiment, the temperature of the fixing roller 90 during continuous fixing is prevented as much as possible by forcibly setting the interval (sheet interval) between sheets during printing in conjunction with the change in the temperature control of the heater. Good fixability was maintained.

Next, the control of this embodiment will be described with reference to the flowchart of FIG.

First, in step S101, the external device 102
When a print instruction is issued from the external device 102, a timer (not shown) for leaving a predetermined sheet interval is started in step S102, and the process proceeds to step S1.
Go to 03 or lower.

Steps S103 to S108 are
The heater temperature is controlled in the same manner as in steps S001 to S006 in FIG. 4 of the first embodiment, but in this embodiment, steps S110, S109, and S111 are performed after steps S105, S107, and S108, respectively.
Followed by These steps S110, S109, S111
Is a paper feed permission timing waiting process for setting a printing interval according to conditions.

When both the heater 104 and the heater 105 are normal In step S110, a paper feed permission wait 1 is executed. That is, it is necessary to wait for a time for keeping the fastest printing interval of the laser beam printer 201.

When only the sub-heater 105 is normal In step S109, a paper feed permission wait 2 is executed. That is, even if only the sub-heater 105 is turned on, the fixing roller 90
In order to maintain a temperature at which the image can be fixed near the central portion of the image, a predetermined time interval between paper sheets is waited.

When Only the Main Heater 104 is Normal In step S111, a paper feed permission wait 3 is executed. That is, even if only the main heater 104 is turned on, the fixing roller 9
In order to maintain the temperature at which the image can be fixed in the vicinity of the end of 0, it is necessary to wait for a predetermined time interval between the sheets.

These steps S110, S109, S1
After waiting for the time at 11, the process proceeds to step S112, and a paper feed permission for the next printing is issued.

As described above, by adjusting the paper interval at the time of printing according to the failure state of the heater, when printing one sheet, the heat of the portion of the fixing roller 90 that is not heated by the normal light distribution of the heater is printed. Even if the paper is robbed by the paper, heat is conducted to the entire area in the longitudinal direction of the fixing roller 90 until the next printing, so that the temperature distribution on the surface of the fixing roller 90 becomes uniform.

(Third Embodiment) Next, a third embodiment of the present invention will be described with reference to FIGS. 1 and 2 and the flowchart of FIG. In the present embodiment, the configuration of the laser beam printer is the same as that of FIG. 2, the configuration of the control circuit is the same as that of FIG. 1, and only the printability determination criterion of the printability determination unit 118 is different.

In the above-described second embodiment, when one of the heaters fails, the operation at the time of fixing, that is, the temperature control of the heater is changed, and the space between the sheets at the time of printing is forcibly removed. I was On the other hand, in the third embodiment, the determination is made by adding a paper type (paper type) element to the determination criterion of the printability determining unit 118. This is because, even if the fixing operation, that is, changing the temperature control of the heater or forcibly spacing the sheets, may not be able to achieve the predetermined fixing property, the limitation is set depending on the type of paper at the stage of determining the printability. It is intended to be added.

The control of the printability determining means 118 of this embodiment will be described next with reference to the flowchart of FIG.

First, steps S201 to S20
At 3, the state of the main heater 104 and the sub-heater 105 is checked. If both the heaters 104 and 105 are normal, the process proceeds to step S206, and printing of paper of all sizes is enabled as usual.

If only the sub-heater 105 is normal, the flow advances to step S205 to enable printing only on a wide sheet. The definition of the paper width in this case is obtained in advance by an experiment or the like.

If only the main heater 104 is normal, the flow advances to step S207 to enable printing only on a narrow recording paper. The definition of the paper width in this case is obtained in advance by an experiment or the like.

When both heaters 104 and 105 fail, it is determined that printing is impossible, and printing is stopped.

After it is determined that printing is possible, the printing operation is performed in accordance with the above-described first embodiment (see FIG. 4) or the second embodiment (see FIG. 5).

According to the present embodiment, by adding the paper type to the criterion for determining the feasibility of printing, printing is performed only on the recording paper having a predetermined fixability, so that printing with poor fixability is not performed.

In the present embodiment, only the paper size is used as a reference, but the paper thickness, paper quality, etc. may be similarly added to the printability determination standard.

(Fourth Embodiment) Next, a fourth embodiment of the present invention will be described with reference to FIGS. 1 and 2 and the flowchart of FIG. In this embodiment, the configuration of the laser beam printer is the same as that of FIG. 2, the control circuit configuration is the same as that of FIG. 1, and only the control content of the state management unit 110 is different.

In the above-described embodiment, all the heaters 10
Only when the failure occurs in the external device 1 or 105,
In this embodiment, the warning information is output to the external device 102 while the printable state is maintained even when some of the heaters fail. did.

The control of the state management means 102 of this embodiment will be described next with reference to the flowchart of FIG.

First, steps S301 to S30
In step 3, the statuses of the main heater 104 and the sub heater 105 are checked. If both the heaters 104 and 105 are out of order, the process proceeds to step S304 to output fault information to the external device 102 as a printer not ready.

On the other hand, if only the sub-heater 105 is normal, the flow advances to step S305 to output information on the failure of the main heater 104 to the external device 102 while holding the printer ready.

If only the main heater 104 is normal, the process proceeds to step S307, and the information on the failure of the sub heater 105 is transmitted to the external device 102 while holding the printer ready.
Output to

According to the present embodiment, the state management means 110
Is performed as described above, so that all the heaters 1
Before a failure occurs in the heaters 04 and 105 and complete printing becomes impossible, a warning is issued to the outside even if some heaters fail.

[0081]

As described above, the first embodiment according to the present application is described.
According to the invention, when the printability determining means determines that printing is possible when some of the plurality of heaters have failed, the print control means performs printing different from the case where all heaters are normal. Perform control. That is, even when some of the heaters fail, printing can be continued while maintaining the predetermined fixing property.

According to the second aspect of the present invention,
The printing control means of the first invention controls the temperature of the heater so as to correct the deviation of the light distribution of the remaining normal heater. Therefore, even if some of the heaters fail, printing can be continued while maintaining the predetermined fixing property.

According to the third aspect of the present invention,
The printing control means of the second invention forcibly increases the interval between sheets of printing, so that even if the heat of the fixing roller is taken away by the sheet, the temperature of the entire area of the fixing roller until the next sheet is fixed. The distribution is made uniform. Therefore, even if some heaters fail during continuous fixing,
Printing can be continued while maintaining a predetermined fixing property.

According to the fourth aspect of the present invention,
The printability determining means of the first invention adds the type of paper to be printed to the determination condition in addition to the remaining normal heater,
Determine printability. That is, by limiting the type of paper to be printed at the stage of determining the feasibility of printing, printing can be continued while maintaining the fixability even when some of the heaters fail.

According to the fifth invention of the present application,
In the first invention, even when some of the heaters are out of order, the state management unit continues the printable state while issuing a warning of the occurrence of a heater abnormality. In other words, before all the heaters fail and printing is not completely possible, a warning is issued to the outside even if only some of the heaters fail, so that all the heaters fail and printing becomes completely impossible. Take corrective action such as repair before.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a control circuit of a printing apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram illustrating an entire printing apparatus including the control circuit of FIG. 1;

3A and 3B are diagrams showing a heater configuration and operation of a fixing device of the printing apparatus of FIG. 2, wherein FIG. 3A is a schematic configuration diagram showing the entire roller configuration, and FIG. 3B is a light distribution distribution diagram of a main heater. ,
(C) is a light distribution diagram of the sub-heater.

FIG. 4 is a flowchart illustrating print control according to the first embodiment of FIG. 1;

FIG. 5 is a flowchart illustrating print control according to a second embodiment of the present invention.

FIG. 6 is a flowchart illustrating control of printability determination according to a third embodiment of the present invention.

FIG. 7 is a flowchart showing control of state management according to the fourth embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 90 fixing roller 91 pressure roller 101 engine main control unit 102 external device 104 main heater 105 sub-heater 110 state management unit 111 print control unit 115 main heater failure detection unit 116 sub-heater failure detection unit 118 printability determination unit 201 laser beam printer ( (Printing device) 213 Fixing device (Fixing device)

Claims (5)

[Claims] In a printing apparatus provided with a fixing device having a plurality of heaters having different light distributions in a longitudinal direction,
Heater failure detection means for outputting a signal for independently detecting a failure for each of the plurality of heaters, and whether printing is possible when some of the heaters fail based on a detection signal input from the heater failure detection means Printability judgment means for judging whether or not, and when the printability judgment means judges that printing is possible, printing is continued by printing control different from that when all heaters are normal so that good fixing performance is maintained. A print control unit configured to stop printing when it is determined that printing is not possible. 2. The printing control device according to claim 1, wherein when it is determined that printing is possible when some of the heaters have failed, the temperature control of the heaters is performed so as to correct the deviation of the light distribution of the remaining heaters. The printing device according to claim 1, wherein the setting is performed. 3. The printing control means according to claim 2, wherein when it is determined that printing is possible when some of the heaters fail, the printing paper interval is forcibly set to be large. The printing device according to the above. 4. The printability determining means is set to determine the printability by adding the type of paper to be printed together with the normal heater remaining when some of the heaters have failed, to the determination conditions. The printing device according to claim 1, wherein 5. A state management means for continuing a printable state while issuing a warning of occurrence of a heater abnormality when the printability determination means determines that printing is possible when some of the heaters fail. The printing device according to claim 1, wherein: