JP4848908B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus, and more particularly to control of a cooling air blower provided to suppress a temperature rise in an optical scanning device or the like.

  Conventionally, an optical scanning device that performs optical scanning by rotating a polygon mirror with a motor has the following problems. That is, a polygon mirror rotating motor (hereinafter referred to as a polygon motor) inside the optical scanning device generates heat during its operation, and the temperature inside the optical scanning device is warmed up gradually. At this time, if the amount of heat radiation from the optical scanning device to the external space is small, the temperature inside the optical scanning device will rise excessively, resulting in thermal expansion distortion in the optical components and the housing, and the performance will be significantly degraded. There is a risk of doing. Therefore, it is important to quickly release the heat generated by the polygon motor inside the optical scanning apparatus to the outside of the optical scanning apparatus.

  However, the optical scanning device generally has a sealed structure. This is because if even a small amount of dust adheres to the surface of the optical component inside the optical scanning device, the light may be partially blocked or scattered, resulting in significant performance degradation. This is because it is ideal that the internal space be completely isolated from the dusty external space. However, on the other hand, since the internal air does not escape to the outside, there is a problem that heat is easily trapped if heat is generated inside.

  Therefore, a means for efficiently exhausting only the internal heat to the outside while blocking the air flow inside and outside the optical scanning device is important. For example, a method of exhausting heat with a heat transport element such as a heat pipe, a method of providing cooling fins or the like on the outer wall surface of the optical scanning device casing, a method of flowing air around the optical scanning device casing with an electric fan, or A method of combining these is well known. Each method has its advantages and disadvantages, such as heat dissipation effect, introduction cost, design layout constraints, etc. However, the electric fan method is advantageous in terms of cost-effectiveness, and it has been widely adopted so far. Yes.

  By the way, as described above, the optical scanning device is ideally in a completely sealed state, but actually, it is often left in a slightly incompletely sealed state. The reason for this is that the more cost is required to achieve a completely sealed state. In practice, it is extremely rare that the air outside the optical scanning device is covered with dust, and in most cases, it is considered that the air is almost the same as or slightly larger than the daily life space. Therefore, even if external air flows into the optical scanning device, it is extremely unlikely that the optical scanning device will immediately become unusable, but rather gradually gradually in proportion to the total amount of external air flowing into the internal space. It is believed that the deterioration progresses and eventually becomes unusable. Therefore, in the case of an optical scanning device designed especially for cost reduction, the sealing performance is reduced to a lower cost at the expense of the fitting portion between the housing and the lid and the minute hole of the housing. In many cases, this method is adopted. Even in such a case, the total amount of external air that will enter the interior of the optical scanning device by the end of its design life is small, that is, the estimated final degree of internal dust contamination is within a sufficiently acceptable range. If so, the quality of the optical scanning device can be considered to be practically sufficient.

  However, the above is based on the assumption that the air around the optical scanning device hardly moves. However, when an air flow is generated around the optical scanning device with an electric fan or the like, a slight atmospheric pressure difference is generated inside and outside the optical scanning device. It will increase compared to the case where it hardly moves. At this time, the total amount of air entering the inside of the optical scanning device increases in proportion to the product of the flow velocity of the air flowing around the optical scanning device and the flowing time. In other words, the greater the amount of air generated by the electric fan and the longer the operating time of the electric fan, the greater the degree of dust contamination inside the optical scanning device.

  As described above, it is desired to blow with an electric fan to prevent overheating of the optical scanning device. However, from the viewpoint of dust contamination, there has been a demand to reduce the air volume of the electric fan as much as possible and to shorten the operation time as much as possible.

  In addition to the above circumstances, there was also a request from the viewpoint of preventing condensation. OA equipment incorporating an optical scanning device is usually assumed to be used indoors. However, there are actually various usage environments and usage forms of end-user OA devices. In an extreme example, there may be a case where the device is used in a semi-outdoor without an outer wall, or a case where the device is temporarily moved from the indoor to the outdoor. Even indoors, there may be extreme daily temperature differences.

  Such use environment / use form causes various problems, but in particular, when the environmental temperature rapidly rises in a short time, the occurrence of condensation is inevitable. Therefore, usually, the OA equipment and the optical scanning device mounted thereon are devised so that the operation can be started in as short a time as possible even if there is some condensation, but if the degree of condensation is severe, There is also a high possibility of falling into an unrecoverable state. By the way, dew condensation is a phenomenon that occurs when a cooled target part comes into contact with the surrounding warm and humid air. Therefore, even if the OA device is used in the environment / configuration as described above, the degree of dew condensation on the internal components of the device due to condensation is reduced by preventing air outside the OA device from entering the OA device. It is possible. However, if an air flow is generated around the optical scanning device by an electric fan, the air inside the OA device moves along with this, so that the air outside the OA device easily flows into the inside. . Therefore, under conditions where dew condensation is assumed, there has been a demand to minimize the air volume of the electric fan of the optical scanning device and to completely stop it if possible.

Therefore, in the case of preventing the optical scanning device from being overheated by the electric fan, several fan control methods for shortening the operation time of the electric fan as much as possible have been devised and put into practical use. For example,
(1) When the temperature of the optical scanning device is lower than a predetermined threshold temperature, the electric fan is stopped to prevent dust contamination.
(2) When the temperature of the optical scanning device is equal to or higher than a predetermined threshold temperature, the optical scanning device is cooled by rotating the electric fan.
It is something like that.

In addition to the above,
(3) In some cases, the electric fan is rotated only when the temperature of the optical scanning device is equal to or higher than a predetermined threshold temperature and when the polygon motor of the optical scanning device is activated. In this case, since the heat source of the optical scanning device is mainly a polygon motor, the operation time of the electric fan is further shortened, and the dust contamination preventing effect is further enhanced.

  By the way, when an electric fan is used for cooling the optical scanning device, if a failure occurs in the electric fan, a predetermined cooling effect cannot be obtained and the optical scanning device is overheated. Therefore, a means for detecting when an abnormality occurs in the heat radiating fan by some method is necessary. For this reason, in many electric fans, an abnormality detection signal is output to indicate whether the electric fan is operating normally or some abnormality has occurred.

  However, even if an abnormality detection signal is used in a single bit, the conditions under which it is output are different for each electric fan, and it depends largely on how the electric fan manufacturer considers the normality / abnormality of the electric fan. . That is, whether it is abnormal only when it is completely stopped and does not move, or whether it rotates only at a rotational speed lower than expected, is included abnormally, if included, what is the determined rotational speed, and the final Although it reaches a predetermined number of revolutions, what to do when it takes a very long time to accelerate to that point, etc. There are slight differences in each manufacturer regarding fine determination conditions.

  Therefore, if the normal / abnormal judgment is made only with the signal level without taking into account the difference in the specification of the abnormality detection signal that differs depending on the electric fan as described above, it may cause troubles such as false detection and detection omission. There is a possibility. Note that false detection and detection omission also occur when noise is applied to the signal line of the abnormality detection signal. Therefore, in order to eliminate the influence of the specification and noise of the electric fan abnormality detection signal, conventionally, in the electric fan abnormality detection determination, “the state determination of the abnormality detection signal is continuously repeated at a predetermined interval (for example, every 1 second). When the number of times indicating an abnormality is equal to or greater than a predetermined number (for example, 60 times), it is finally determined that an abnormality has occurred in the fan, and predetermined processing (such as FAN failure notification) is performed. Such an abnormality detection sequence has been adopted.

  6 to 8 are diagrams for explaining conventional examples of failure detection.

In the conventional fan control method of the optical scanning device, when the control is performed under the condition (3), the heat radiating fan operates only while the polygon motor is rotating. Therefore, in the conventional electric fan abnormality detection sequence, if there is a case where the polygon motor rotates only for a very short time, a case where the abnormality detection of the electric fan cannot be determined (detection omission) occurs. Accordingly, when the abnormality detection signal state determination execution interval is Ti, the cumulative number of abnormalities for final determination of abnormality is P, and the minimum rotation time of the polygon motor is Tm, the abnormality detection failure of the electric fan does not occur. The condition is Tm> Ti × P (1)
Is established. For example, if Tm is 5 seconds and Ti is 1 second, P must be 4 times or less.

  However, the rotation time of the polygon motor is not always constant. In some cases, it may continue to rotate for a very long time. Even in such a case, the above equation (1) is established without any problem and no detection omission occurs, but this time, the possibility of erroneous detection due to noise mixing in the signal line is increased. For example, assume that the rotation time Tm of the polygon motor is 30 minutes (1800 seconds) in the above example. During this time, if noise is intermittently mixed in the signal line of the abnormality detection signal, a determination error may occur if the timing of the noise mixing and the state determination of the abnormal signal exactly overlaps. If the probability of this determination error occurring is once every five minutes on average, about 20 minutes after the electric fan has rotated, the electric fan is actually normal, but it is erroneously detected as abnormal. Will end up.

  Such erroneous detection can be prevented by increasing the set value of Ti or P. This is because if Ti is increased, the frequency of noise mixing and abnormal signal state determination timing overlaps decreases, and if P is increased, the delay until final determination is increased.

  However, if Ti and P are made too large, the above equation (1) will not be satisfied if Tm is short, that is, the first problem, detection omission occurs, and the selection of Ti and P values is very There was a problem that it was difficult.

In order to solve the above-described object, an invention according to claim 1 is directed to an optical scanning device that scans a laser beam at a predetermined position, and an air blower that cools the optical scanning device or component parts constituting the optical scanning device. And a signal determining means for determining whether or not the signal level of the state detection signal according to the state of the blower means output from the blower means is abnormal for each predetermined interval Ti , the first count value is reset immediately after the abnormality determination sequence to determine the status of the operation is started, it counts up the first count value when the signal level of the state detection signal indicating abnormality, the state not reset the first counter signal level of the detection signal for resetting said first count value when indicating the normal, the second count value immediately after the abnormality determination sequence is initiated , When the first count value was less than the first predetermined value N and a second predetermined value M (M <N) or more, a second counter for counting up the second count value, and abnormality determining means for determining that an abnormality has occurred, the second count value is abnormal when the above predetermined value P generated in the first count value said first of said blowing means when a predetermined value or more N A warning unit that determines that there is a possibility and generates a warning, and a control that starts the operation of the blower unit, and a control that starts the abnormality determination sequence after the blower unit starts the operation. And a control means .

According to the first aspect of the present invention, the signal determination means determines whether or not the signal level of the state detection signal corresponding to the state of the blower means output from the blower means is abnormal for each predetermined interval Ti. The first counter counts up the first count value when the signal level of the state detection signal indicates an abnormality, and when the signal level of the state detection signal indicates normal and when the operation starts and ends The first count value is reset, and the abnormality determination unit determines that an abnormality has occurred in the blower unit when the first count value is equal to or greater than the first predetermined value N, so that an erroneous detection related to a past state occurs. Without abnormality, it is possible to determine the abnormality of the air blowing means more accurately.

According to the first aspect of the present invention, the second counter is configured when the first count value is less than the first predetermined value N and greater than or equal to the second predetermined value M (M <N). The second count value is counted up, and the warning means determines that an abnormality may occur when the count value of 2 is equal to or greater than the predetermined value P, and generates a warning. Prior to this, it is possible to warn that an abnormality may occur in the blowing means.

In order to achieve the above object, an invention described in claim 2 is directed to an optical scanning device that scans a laser beam at a predetermined position, and to cool the optical scanning device or component parts constituting the optical scanning device. A blower means, a signal determination means for judging whether or not a signal level of a state detection signal according to the state of the blower means output from the blower means indicates an abnormality, and the blower means The first count value is reset immediately after the abnormality determination sequence for determining the state of the operation is started, and when the signal level of the state detection signal indicates an abnormality, the first count value is counted up, and the state a first counter signal level of the detection signal for resetting said first count value when indicating normality, without resetting the second count value immediately after the abnormality determination sequence is initiated In a predetermined period of time Ts (Ts> Ti), wherein when the first count value was less than the first predetermined value N and a second predetermined value M (M <N) or more, the second count value the counted up, and a second counter for resetting said second count value each time the predetermined time period Ts has elapsed, the first count value said first predetermined value N or more when the blowing means An abnormality determining means for determining that an abnormality has occurred, and a frequency obtained by dividing the second count value in the predetermined period Ts by the value of the predetermined period Ts is equal to or greater than a predetermined value R. A warning means for generating a warning by determining that there is a possibility that an abnormality may occur, and controlling the blower means to start operation, and after the blower means starts operating, the abnormality determination sequence Control to start It is characterized by comprising a control means.

According to the invention described in claim 2, the signal determination means determines whether or not the signal level of the state detection signal according to the state of the blower means output from the blower means indicates an abnormality at every predetermined interval Ti. The first counter counts up the first count value when the signal level of the state detection signal indicates an abnormality, and when the signal level of the state detection signal indicates normal and when the operation starts and ends The first count value is reset, and the abnormality determination unit determines that an abnormality has occurred in the blower unit when the first count value is equal to or greater than the first predetermined value N, so that an erroneous detection related to a past state occurs. Without abnormality, it is possible to determine the abnormality of the air blowing means more accurately.

According to the second aspect of the present invention, the second counter has a first count value less than the first predetermined value N and a second predetermined value M in a predetermined period Ts (Ts> Ti). If (M <N) or more, the second count value is counted up, the second count value is reset every time the predetermined period Ts elapses, and the warning means outputs the second count value during the predetermined period Ts. When the frequency obtained by dividing the count value of 2 by the value of the predetermined period Ts is equal to or greater than the predetermined value R, it is determined that an abnormality may occur, and a warning is generated. Prior to the occurrence of an abnormality, it is possible to warn that an abnormality may occur in the blowing means.

The invention according to claim 3 is characterized in that, in the invention according to claim 1 or claim 2 , the abnormality determining means makes a determination only while the air blowing means is in operation. ing.

According to the third aspect of the present invention, since the abnormality determination is not performed when the air blowing means is not in operation, it is possible to reduce the CPU resources consumed for the abnormality determination or to distribute them to other work. It becomes possible.

The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the time Ton from when the air blowing means starts operating until it stops and the predetermined interval. It is characterized in that a relationship of Ton ≧ Ti × N is established between Ti and a predetermined number of times N.

According to the fourth aspect of the present invention, detection failure does not occur regardless of the operating time of the air blowing means, and it is possible to determine the abnormality of the air blowing means more accurately.

Further, in the invention according to claim 5 , in the invention according to any one of claims 1 to 4 , when the abnormality determining means determines that an abnormality has occurred in the air blowing means, a predetermined number or less. It is characterized in that only the image output operation is accepted.

Furthermore, in the invention according to claim 6 , in the invention according to any one of claims 1 to 4 , when the abnormality determining unit determines that an abnormality has occurred in the blowing unit, the previous image is displayed. A feature is that the next image output operation is performed after a predetermined time from the end of the output operation.

Further, in the invention according to claim 7 , in the invention according to any one of claims 1 to 6 , when the abnormality determining means determines that an abnormality has occurred in the blowing means, one image is taken. It is characterized in that the image output operation is performed with a predetermined interval for each output.

Furthermore, the invention according to claim 8 is the image forming apparatus according to any one of claims 1 to 7 , wherein the abnormality determining unit determines that an abnormality has occurred in the blowing unit. The image output operation is performed only when the temperature output value of the temperature sensor provided in is equal to or less than a predetermined value.

According to the invention of any one of claims 5 to 8 , even if the abnormality determining means finally determines that an abnormality has occurred in the air blowing means, a condition range in which the temperature of the optical scanning device does not increase excessively. Since the image output is permitted in the user, the convenience of the user can be improved as compared with the case where the operation is completely stopped.

  According to the present invention, it is possible to accurately determine whether or not an abnormality has occurred in the overheating preventing air blowing means of the optical scanning device without erroneous detection or detection omission. Even in this case, reliability and safety can be ensured without causing the optical scanning device to fail. Further, as an emergency response, the optical scanning device can be operated within a range where no air blowing is required, so that a reduction in productivity can be minimized.

[First embodiment of the present invention]
Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 shows an embodiment of an image forming apparatus according to the present invention. Reference numeral 1 denotes an optical scanning device, reference numeral 2 denotes a light source, reference numeral 3 denotes a window glass, reference numeral 4 denotes a polygon motor, reference numeral 5 denotes a polygon motor driving power source, reference numeral 6. Is a general control unit, 7 is a blower control switch, 8 is a blower, and 9 is a blower power supply. In FIG. 1, a light beam emitted from a light source 2 mounted on the optical scanning device 1 is deflected and scanned by a polygon mirror of a polygon motor 4, passes through an optical component (not shown), and then passes through a window glass 3. Irradiated to a scanning object (not shown) outside the optical scanning device 1.

  A blower 8 is arranged outside the optical scanning device 1, and the wind generated by the blower 8 is blown toward the outer wall surface of the optical scanning device 1. The blower 8 generates an abnormality detection signal and outputs it to the overall control unit 6.

  The overall control unit 6 controls the power supplied from the blower power supply 9 to the blower 8 by switching the blower control switch 7 and controls whether or not to send the wind to the optical scanning device 1. The overall control unit 6 inspects the abnormality detection signal output from the blower 8 at regular intervals to determine whether the operation of the blower 8 is normal or abnormal. Further, the overall control unit 6 outputs a control signal and an image signal to the optical scanning device 1 to perform rotation / stop control of the polygon motor 4, rotation speed control, and light emission control of the light source 2.

  Next, the operation of the image control apparatus of this embodiment will be described. In this embodiment, the overall control unit 6 starts rotation of the polygon motor 4 inside the optical scanning device 1 when a certain predetermined condition (light scanning start condition) is reached, and controls the lighting of the light source 2, Optical scanning is performed on the scanning target outside the optical scanning device 1. At this time, if the overall control unit 6 determines that the temperature inside the optical scanning device 1 is equal to or higher than a predetermined temperature (cooling start temperature), the blower control switch 7 is turned on to operate the blower 8 to perform optical scanning. Air is sent to the outer wall surface of the apparatus 1 to cool the optical scanning apparatus 1.

  At this time, the blower 8 starts outputting an abnormality detection signal immediately after the operation starts, and the overall control unit 6 determines whether the blower 8 is operating normally or abnormally. Further, the overall control unit 6 determines whether or not the temperature inside the optical scanning device 1 is equal to or lower than a predetermined temperature (cooling end temperature). The apparatus 8 is stopped and the cooling of the optical scanning apparatus 1 is finished.

  Further, when the overall control unit 6 reaches a certain predetermined condition (light scanning end condition), the rotation of the polygon motor 4 inside the light scanning device 1 is stopped, and the lighting control of the light source 8 is finished. 1 optical scanning is stopped. In addition, when the air blower 8 is operating at this time, after continuing operating the air blower 8 only for predetermined time (cutting delay time), the air blow control switch 7 is turned off and the air blower 8 is stopped.

  Next, the abnormality determination method of the air blower 8 of a present Example is demonstrated using FIG.

  When the overall control unit 6 turns on the air blowing control switch 7 and starts the operation of the air blowing device 8, the air blowing device 8 outputs an abnormality detection signal. Subsequently, the overall control unit 6 starts executing the abnormality determination sequence. First, the internal counter is reset immediately after the start of execution of the abnormality determination sequence (S101).

  Next, the determination of the signal level of the abnormality detection signal is periodically repeated based on the generation timing of the internal clock (S102, S103). In this embodiment, the generation timing of the internal clock and the control timing of the blower control switch 7 are not synchronized at all, so the time from the operation start timing of the blower 8 until the first abnormality detection signal level determination is performed. G is different each time the blower 8 is activated. (Note that 0 ≦ G <t (= Ti), where t is the repetition time of abnormality detection signal level determination, that is, the cycle t of the internal clock). In addition, there is a relationship of Ton ≧ Ti × N between the time Ton from when the blower 8 starts operating until it stops and the predetermined interval Ti and the predetermined number N.

  Next, appropriate processing is performed based on the abnormality determination signal level determination result. First, when the determination result (S104) is H, that is, a value indicating abnormality, the counter is incremented by 1 (count up: S105). If the determination result (S104) is L, that is, a value indicating normality, the counter is reset to zero (S101).

  Next, the value of the counter is compared with a predetermined number N (S106). As a result, when the value of the counter is equal to or greater than N, it is determined that an abnormality has occurred in the blower 8 (determined that the final determination result is “abnormal”), and the abnormality determination sequence is immediately terminated to fail as described later. A processing sequence is executed (S107).

  If the value of the counter is less than N, nothing is done (it is determined that the final determination result is not “abnormal”), and the next internal clock is awaited. Thereafter, whenever the internal clock is generated, the above-described signal level determination of the abnormality detection signal is repeated.

  When the air blow control switch 7 is turned off during the execution of the abnormality detection sequence described above, that is, when the air blower 8 is stopped, the abnormality detection sequence is immediately terminated.

  FIG. 3 shows an example of an abnormality determination method that indicates that the final determination is changed to an abnormality when it occurs continuously N times or more. FIGS. 4 and 5 also illustrate the FAN rotation / expansion time for determining an abnormality in the final determination.

Next, the fail processing sequence will be described. In the above-described abnormality detection sequence, when the value of the counter becomes N or more, the failure processing sequence is executed on the assumption that an abnormality of the blower 8 has occurred. In the fail processing sequence of the present embodiment, first, the blow control switch 7 is immediately turned off, and the power supply to the blower 8 is completely cut. Next, a display regarding the occurrence of an error is performed on a display unit of the image control apparatus main body (not shown). Finally, almost all power supplies other than the minimum necessary power supply line are cut off, and the apparatus waits in a state where its own power consumption is reduced to the limit.
[Second embodiment of the present invention]
Subsequently, a second embodiment of the present invention will be described in detail. Note that the configuration and operation of the second embodiment of the present invention are substantially the same as those of the first embodiment, and thus detailed description thereof is omitted.

  Next, an abnormality determination method for the blower 8 according to the second embodiment of the present invention will be described.

  When the overall control unit 6 turns on the air blowing control switch 7 and starts the operation of the air blowing device 8, the air blowing device 8 outputs an abnormality detection signal. Subsequently, the overall control unit 6 starts executing the abnormality determination sequence. First, the first internal counter is reset immediately after the execution of the abnormality determination sequence.

Next, the determination of the signal level of the abnormality detection signal is periodically repeated based on the generation timing of the internal clock. In this embodiment, the generation timing of the internal clock and the control timing of the blower control switch 7 are not synchronized at all, so the time from the operation start timing of the blower 8 until the first abnormality detection signal level determination is performed. G is different each time the blower 8 is activated. (Note that 0 ≦ G <t, where t is the repetition time of abnormality detection signal level determination, that is, the period t of the internal clock)
Next, appropriate processing is performed based on the abnormality determination signal level determination result. First, when the determination result is H, that is, a value indicating abnormality, the first counter is incremented by 1 (counting up). If the determination result is L, that is, a value indicating normality, the first counter is reset to zero.

  Next, the value of the first counter is compared with predetermined values M and N (M <N).

  As a result, if the value of the first counter is equal to or greater than N, it is determined that an abnormality has occurred in the blower 8 (the final determination result is “abnormal”), and the abnormality determination sequence is immediately terminated to fail as described later. Execute the processing sequence.

  If the value of the first counter is less than N and greater than or equal to M, the second counter is incremented by 1 (counting up). Then, the value of the second counter is compared with a predetermined value P. As a result, when the value of the second counter is equal to or greater than P, it is determined that there is a high possibility that an abnormality occurs in the blower 8 (the final determination result is “warning”), and an alert processing sequence described later is executed. To start. In this case, the abnormality determination sequence is not terminated and the execution is continued in parallel with the alert processing sequence. That is, after the execution of the alert processing sequence is started, the above-described abnormality detection signal level determination is repeated after the next internal clock is generated.

  Note that the second counter is not reset immediately after the execution of each abnormality determination sequence, and retains the value at the time of the previous abnormality determination, but the operating time of the blower 8 has elapsed a predetermined time Ts. A reset is performed each time. Therefore, the alert processing sequence is executed when the frequency at which the abnormality detection signal level is determined to be abnormal is equal to or higher than a predetermined frequency determined by M / Ts.

  Next, when the value of the counter is less than M, nothing is done (the final determination result is “normal”), and the next internal clock is generated. Thereafter, the above-described abnormality detection signal level determination is repeated every time an internal clock is generated.

  When the air blow control switch 7 is turned off during the execution of the abnormality detection sequence described above, that is, when the air blower 8 is stopped, the abnormality detection sequence is immediately terminated.

  Next, the fail processing sequence will be described. In the above-described abnormality detection sequence, when the value of the first counter becomes N or more, the failure processing sequence is executed on the assumption that an abnormality of the blower 8 has occurred. In the fail processing sequence of the present embodiment, first, the blow control switch 7 is immediately turned off, and the power supply to the blower 8 is completely cut. Next, a display relating to the occurrence of an error is performed on a display unit of the image control apparatus main body (not shown). Finally, almost all power supplies other than the minimum necessary power supply line are cut off, and the apparatus waits in a state where its own power consumption is reduced to the limit.

  Next, the alert processing sequence will be described.

  In the above-described abnormality detection sequence, when the value of the second counter is equal to or greater than P, it is determined that there is a high possibility that an abnormality occurs in the blower 8, and the alert processing sequence is executed. In the alert processing sequence of the present embodiment, a display to warn of the possibility of error occurrence is displayed on a display unit of the image control apparatus main body (not shown).

As described above, in this embodiment, a warning is given before the blower 8 actually breaks down, so there is a margin to prepare for the failure of the blower 8 in advance. Therefore, it is possible to shorten as much as possible the period during which the air blower 8 suddenly breaks down and the image output is completely impossible until the service engineer is called and the repair work is completed.
[Third embodiment of the present invention]
Subsequently, a third embodiment of the present invention will be described in detail. Note that the configuration, operation, and abnormality determination method of the third embodiment of the present invention are substantially the same as those of the first embodiment, and thus detailed description thereof is omitted.

  Next, a fail processing sequence according to the third embodiment of the present invention will be described.

  In the abnormality detection sequence, when the value of the first counter becomes N or more, the failure processing sequence is executed on the assumption that an abnormality of the blower 8 has occurred. In the fail processing sequence of the present embodiment, first, the blow control switch 7 is immediately turned off, and the power supply to the blower 8 is completely cut. Next, a display relating to the occurrence of an error is performed on a display unit of the image control apparatus main body (not shown). Then, a condition for the overall control unit 6 to start the rotation of the polygon motor 4 inside the optical scanning device 1 is added. That is, the condition is that “the polygon motor 4 is not newly started to rotate until the predetermined time Tz elapses after the previous stop of the polygon motor 4”. As a result, even when a command to continuously output images is received from the image forming apparatus, the polygon motor 4 is stopped for a predetermined time Tz every time one image is output.

  Therefore, it is possible to prevent a situation where the internal temperature of the optical scanning device 1 rises excessively. This operation is performed in consideration of the convenience of the user so that the image can be output as much as possible even when the blower 8 suddenly breaks down. Measures. Especially when the image forming device also serves as a device that receives faxes, even if there are no people around, such as at night, it can be output without failing, and important information may be lost. There is a merit that there is no.

  The polygon motor 4 of the first embodiment, the second embodiment, and the third embodiment of the present invention is entirely inside the optical scanning device 1, but is a part of the polygon motor 4. Even if the configuration is exposed to the outside of the optical scanning device 1, the same operation as described above can be obtained. In addition, although the air generated by the blower 8 is blown directly on the optical scanning device 1, it may be indirectly actuated using an appropriate rectifying plate or duct. Further, the direction of the air flow may be reversed and the air scanning device 1 may not be blown, but rather wind may be sucked.

It is a block diagram of one Example of this invention. It is a figure which shows an example of the abnormality determination method of this invention. It is a figure explaining the abnormality determination method of this invention. It is a figure explaining the abnormality determination method of this invention. It is a figure explaining the abnormality determination method of this invention. It is a figure explaining a prior art example. It is a figure explaining a prior art example. It is a figure explaining a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical scanning device 2 Light source 3 Window glass 4 Polygon motor 5 Polygon motor drive power source 6 Overall control unit 7 Blower control switch 8 Blower device 9 Blower device power source

Claims (8)

An optical scanning device that scans a laser beam at a predetermined position;
An air blowing means for cooling the optical scanning device or component parts constituting the optical scanning device;
A signal determination means for determining whether or not the signal level of the state detection signal according to the state of the blower means output from the blower means indicates an abnormality, and a predetermined interval Ti;
Reset the first count value immediately after the abnormality determination sequence to determine the status of operation of said blowing means is started, counting the first count value when the signal level of the state detection signal indicating abnormality A first counter that resets the first count value when a signal level of the state detection signal indicates normal;
The second count value is not reset immediately after the abnormality determination sequence is started, and the first count value is less than the first predetermined value N and equal to or greater than the second predetermined value M (M <N). If, a second counter for counting up the second count value,
And abnormality determining means for determining that an abnormality has occurred in the blowing means when said first count value is equal to or greater than the first predetermined value N,
Warning means for determining that there is a possibility of an abnormality when the second count value is equal to or greater than a predetermined value P and generating a warning;
Control means for controlling the air blowing means to start operation, and for controlling to start the abnormality determination sequence after the air blowing means starts operation;
An image forming apparatus comprising: An optical scanning device that scans a laser beam at a predetermined position;
An air blowing means for cooling the optical scanning device or component parts constituting the optical scanning device;
A signal determination means for determining whether or not the signal level of the state detection signal according to the state of the blower means output from the blower means indicates an abnormality, and a predetermined interval Ti;
The first count value is reset immediately after the abnormality determination sequence for determining the operation status of the blower means is started, and when the signal level of the state detection signal indicates an abnormality, the first count value is counted up. A first counter that resets the first count value when the signal level of the state detection signal indicates normal;
The second count value is not reset immediately after the abnormality determination sequence is started , and the first count value is less than the first predetermined value N and the second predetermined value during a predetermined period Ts (Ts> Ti). If was the value M (M <N) or more, a second counter said second count value counted up, resetting said second count value each time the predetermined time period Ts has elapsed,
And abnormality determining means for determining that an abnormality has occurred in the blowing means when said first count value is equal to or greater than the first predetermined value N,
When the frequency obtained by dividing the second count value in the predetermined period Ts by the value of the predetermined period Ts is equal to or greater than the predetermined value R, it is determined that an abnormality may occur. Warning means for generating warnings,
Control means for controlling the air blowing means to start operation, and for controlling to start the abnormality determination sequence after the air blowing means starts operation;
An image forming apparatus comprising:   The image forming apparatus according to claim 1, wherein the abnormality determination unit performs the determination only while the air blowing unit is in operation.   The relationship between Ton ≧ Ti × N is established between the time Ton from the start of operation of the air blowing means to the stop thereof, and the predetermined interval Ti and the predetermined number N. Item 4. The image forming apparatus according to any one of Items 3 to 3.   5. The image forming apparatus according to claim 1, wherein when the abnormality determining unit determines that an abnormality has occurred in the air blowing unit, only an image output operation of a predetermined number or less is accepted.   5. The apparatus according to claim 1, wherein when the abnormality determination unit determines that an abnormality has occurred in the blower unit, the next image output operation is performed after a predetermined time from the end of the previous image output operation. The image forming apparatus described in the item.   7. The image output operation according to claim 1, wherein when the abnormality determining unit determines that an abnormality has occurred in the air blowing unit, an image output operation is performed with a predetermined interval each time an image is output. 2. The image forming apparatus according to item 1.   The image output operation is performed only when a temperature output value of a temperature sensor provided in the image forming apparatus is equal to or less than a predetermined value when the abnormality determination unit determines that an abnormality has occurred in the air blowing unit. The image forming apparatus according to claim 7.

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