JPH1152779A - Illuminator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect deterioration with laspe of time on a connecting section between a condenser and a flash lamp, so as to prevent a significant failure on the connecting section, in an illuminator lighting the flash lamp by accumulated energy in the condenser. SOLUTION: This illuminator is provided with a flash lamp 1, a condenser 2a storing the lighting energy for the lamp 1, a charge voltage detecting means 5 detecting the charge voltage in the condenser 2a, and a connecting section 9 connecting the condenser 2a and the lamp 1. In the above configuration, the illuminator is provided with a discharging resistor 11 connected in parallel with the lamp 1 on the lamp 1 side of the connecting section 9, open/closing means 10a connected in series with the discharging resistor 11, and an optical measuring means 15 measuring the amp lighting illuminance. When the lamp lighting illuminance measured by the optical measuring means 15 becomes below a specified value, the condenser voltage after starting the discharge is detected by the cage voltage detecting means 5 by forming a discharging circuit of the condenser 2a through the discharge resistor 11 on closing the open/closing means 10a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lighting device using a flash lamp such as a strobe light emitter.
The present invention can be applied as a document illumination device or a fixing device of a copying machine, or as a fixing device of a printer.

[0002]

2. Description of the Related Art Heretofore, as one method of a document illuminating device used in a copying machine, for example, a device using a flash lamp such as a strobe light emitting device as a light source is known. This flash lamp has a capacitor in which luminous energy is stored in advance and a flash power supply circuit that stores energy in the capacitor.The trigger circuit turns on the flash lamp to start discharging, and the capacitor of the capacitor is connected via the flash lamp. The accumulated charge is discharged instantaneously to emit a large amount of light instantaneously. The condenser and the flash lamp are connected via a connecting portion including a socket and a plug. Regarding the connection of the flash lamp, the voltage applied to the lamp is a high voltage such as about 2 KV, and
There is a background that the flowing current is a high current of, for example, about 2000 A, and there has conventionally been a problem of deterioration or breakage of the connection portion. This is because high energy is transmitted at a high voltage and a high current, and thus the contact is likely to deteriorate with time. The deterioration of the contact progresses when the number of times of light emission of the lamp overlaps. Furthermore, in order to increase the amount of light emission, the light emission voltage tends to be higher in the specification, and therefore the current also tends to increase. Sometimes. If the connection is maintained and the connection is rechecked in the initial state of deterioration, the deterioration and damage of the connection can be prevented.

[0003] In a lighting device using a flash lamp as described above, there has been proposed a flash lamp connecting device capable of preventing a connection error or a connection failure by devising a structure of a connecting portion. 7-31
No. 514 discloses an elastic means for urging the plug in the plug mounting direction of the flash lamp connector, and the urging force of the elastic means presses the plug against the socket so that the plug and the socket are securely contacted. It is like that.

[0004]

With the flash lamp connecting device described in the above publication, the plug is pressed against the socket via elastic means for urging the plug in the mounting direction of the input plug and fixed. Therefore, the plug and the socket can be reliably contacted. However, even if a predetermined contact pressure is held by using an elastic means or the like, there is a limit to the prevention of deterioration of the contacts, and the electrical contact resistance between the contacts of the connecting portion increases due to repeated attachment and detachment of the lamp,
Acceleration of deterioration is accelerated by a phenomenon such as an arc.

In connection with the lamp, the lamp-side connector may be screwed to a terminal block or the like. However, a setting error such as forgetting to tighten the screw may occur. If used incorrectly, the flash lamp not only does not emit light, but also the capacitor for storing the lamp emission energy is charged and maintained at a high voltage and with the high energy stored. May cause electric shock to maintenance personnel.

[0006] On the other hand, in the flash lamp light emitting device, it is necessary to be aware that although the light emission failure and deterioration of the lamp do not occur frequently, they can occur. Further, apart from a decisive defect such as that the lamp does not emit light at all, a slight change in the amount of light can sufficiently occur due to many factors relating to the light emission. When precise image irradiation is required, for example, when illuminating a document in a high-quality image processing apparatus, a slight change in the amount of light causes a problem relating to the quality of the image processing apparatus.

Accordingly, the present invention provides a lighting device in which a flash lamp emits light by the energy stored in a capacitor, in which it is possible to judge the deterioration with time of a contact point of a connection portion between the capacitor and the flash lamp. It is an object of the present invention to provide a lighting device that can prevent a serious problem such as breakage of a contact beforehand. It is a further object of the present invention to provide an illuminating device capable of quickly detecting that the amount of irradiation light becomes unstable due to deterioration or failure of the flash lamp itself.

[0008]

In order to achieve the above object, the present invention is directed to a flash lamp, a capacitor for storing luminous energy of the flash lamp, and a charging device for detecting a charging voltage of the capacitor. In a lighting device having a voltage detecting means and a connection portion for connecting a capacitor and a lamp, a discharge resistor connected in parallel to the lamp on the lamp side of the connection portion, and a discharge resistor connected in series to the discharge resistor. Opening / closing means, and optical measuring means for measuring lamp light emission illuminance, and when the lamp light emission illuminance measured by the optical measurement means falls below a set value, the switch means is closed to discharge the capacitor by a discharge resistor. A circuit is formed, and the capacitor voltage after the start of discharging is detected by the charging voltage detecting means.

According to a second aspect of the present invention, a flash lamp, a capacitor for storing luminous energy of the flash lamp, charging voltage detecting means for detecting a charging voltage of the capacitor, and a connecting portion for connecting the capacitor and the lamp are provided. In the lighting device comprising, a discharge resistor connected in parallel with the lamp on the lamp side than the connection portion,
Switching means connected in series to the discharge resistor; a current limiting member provided between the capacitor and the connection portion; and a temperature measuring means for measuring the temperature of the current limiting member. When the temperature of the current limiting member falls below a certain temperature, the opening / closing means is closed to form a capacitor discharging circuit by the discharge resistor, and the capacitor voltage after the start of discharging is detected by the charging voltage detecting means. It is characterized by doing.

According to a third aspect of the present invention, there is provided a flash lamp, a capacitor for storing luminous energy of the flash lamp, charging voltage detecting means for detecting a charging voltage of the capacitor, a connecting portion for connecting the capacitor and the lamp, In a lighting device of an image forming apparatus having a photosensitive member on which a latent image of a document image illuminated by a flash lamp is formed, a discharge resistor connected in parallel to the lamp on the lamp side with respect to the connection portion, An opening / closing means connected in series to the discharge resistor; and a potential measuring means for measuring a potential of a latent image on the photoreceptor, when a potential value of the latent image measured by the potential measuring means exceeds a certain set value. Closing the opening / closing means to form a capacitor discharging circuit by the discharging resistor, and detecting the capacitor voltage after the start of discharging by the charging voltage detecting means. Characterized in that it detects.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a lighting device according to an embodiment of the present invention. First, with reference to FIG. 2, an example of a connecting portion 9 for connecting a capacitor and a flash lamp applicable to the present invention will be described. In FIG. 2, among wires from a flash lamp (not shown), wires 49 from a trigger electrode are used.
Are connected to input plugs 57 of the flash lamp, and wires 50 and 51 from the electrodes of the lamp are connected to input plugs 58 and 59 of the flash lamp, respectively. These input plugs 57, 58, 59 are held with an appropriate degree of freedom via an insulating elastic body 62 by a plug holder 60 as a plug holding means and a plug cover 61. More specifically, the plug holder 60 and the plug cover 61 are connected by screws or the like, are formed substantially integrally, and face each other at a predetermined interval to constitute the electric wire holder 52. Between the plug holder 60 and the plug cover 61, a flange-shaped portion of the elastic body 62 and the input plugs 57, 58, 59 is interposed, and the input plugs 57, 58, 59 are formed by the elastic body 62.
Are urged to the left in FIG.

On the other hand, a socket 63 attached to an end of an electric wire 69 from a trigger unit (not shown) and sockets 64 and 65 attached to ends of electric wires 70 and 71 from a flash power supply (not shown) are fixed to a bracket 66. ing. With the plugs 57, 58, and 59 inserted into the sockets 63, 64, and 65, respectively, the plug holder 60 of the electric wire holder 52 is coupled to the bracket 66 as a socket means by an appropriate means such as a screw. I have. An interval between the socket 63 and the socket 64,
The distance between the socket 64 and the socket 65 is different.
The distance between the plug 57 and the plug 58 held by the plug holder 60 and the plug cover 61 is the same as the distance between the socket 63 and the socket 64, and the distance between the plug 58 and the plug 59 is the distance between the socket 64 and the socket 65. Same as the interval. Therefore, each socket 63, 64,
Plugs 57, 58, 59 can be inserted into 65, respectively, and are not set even if inserted in reverse, so that incorrect connection can be prevented.

As described above, since the plug holder 60 and the plug cover 61 are substantially integrated, each socket 6
In a state where the plug holder 60 is coupled to the bracket 66 with the plugs 57, 58, 59 inserted into 3, 64, 65, respectively, the plugs 57, 58, 59 recede while compressing the elastic body 62, and The body 62 is urged. With this urging force, the plugs 57, 58, 59 are pressed against the sockets 63, 64, 65, respectively,
Electrical connection between 3, 64, 65 and each of the plugs 57, 58, 59 is ensured.

Next, an example of an electric system used in the present invention will be described. In FIG. 2, the flash lamp 1 is, for example, a xenon lamp used as a light source in a so-called strobe light emitter. The flash lamp 1 is connected to a flash power supply 2 via a connection unit 9. A discharge resistor 11 is connected to the flash lamp 1 in parallel with the lamp 1 on the lamp 1 side of the connection portion 9 with respect to the flash power supply 2, and an opening / closing means 10 a is connected to the discharge resistor 11 in series. Here, a make contact of the relay RA is used as the opening / closing means 10a. Inside the flash power supply 2, a capacitor 2a for storing energy for causing the flash lamp 1 to emit light, and a break contact 2b of a relay (not shown) for discharging the stored energy of the capacitor 2a when an abnormality occurs or the like. And a discharge circuit composed of a resistor r3 connected in series. The flash power supply 2 has a power switch 1
The AC power supply 3 is supplied via the power supply 4. The AC power supply 3 is boosted and rectified by the flash power supply 2 and converted into a high-voltage DC power supply.
Is accumulated in

In FIG. 2, a central processing unit (hereinafter, referred to as a “CPU”) 4 includes a charging signal for accumulating luminous energy of the flash lamp 1 and a trigger signal for causing the flash lamp 1 to emit light.
Output to The flash power supply 2 accumulates light emission energy to a predetermined voltage in the capacitor 2a according to a charging signal from the CPU 4 and a charging voltage signal as output data. When charging is completed, charge completion signal is sent from flash power supply 2 to C
Output to PU4. The flash power supply 2 is also connected with resistors R1 and R2 for dividing the voltage of the capacitor 2a,
A charging voltage detecting means 5 for inputting the divided voltage value to the CPU 4 as a voltage detecting signal is provided. An optical measuring means 15 for measuring the illuminance of the light emitted from the lamp is arranged near the flash lamp 1, and light amount data measured by the optical measuring means 15 is input to the CPU 4.

In the flash power supply 2, a condenser 2 is provided.
A current limiting member 19 made of a reactor is provided between the terminal a and the connecting portion 9. The current limiting member 19 limits the current flowing from the condenser 2a to the flash lamp 1, and generates heat by the flowing current. Current limiting member 1
A temperature measuring means 17 for measuring the temperature of the current limiting member 19 is arranged fixedly on or near the current limiting member 19, and the measured temperature data is input to the CPU 4. An emission detection signal is input from the flash power supply 2 to the CPU 4, and an abnormality detection signal is input from the CPU 4 to the flash power supply 2. The CPU 4 controls the energization of the coil 10b of the relay RA via the relay drive circuit 12.

The example shown in FIG. 2 is an example of a lighting device of an image forming apparatus using an electrophotographic process such as a copying machine, a printer, a facsimile or the like. Exposure of the photoconductor 16 causes the image of the original to be formed as a latent image on the surface of the photoconductor 16. In FIG. 2, the photosensitive member 16 is depicted as a drum, but when the original is illuminated by the flash lamp 1, the entire surface of the original is illuminated at a time, and the image of the entire surface of the original is In practice, a photoreceptor belt having a flat portion is used. FIG. 2 conceptually depicts the photoconductor 16 only in the electric system diagram. The surface of the photoconductor 16 is uniformly charged in advance by the charger 20, and the image of the document is formed as a latent image by the above exposure. This latent image undergoes a predetermined electrophotographic process including a development process, a transfer process,
The same image as the original image is reproduced on the transfer paper. The photosensitive drum 16 further goes through a cleaning process to a charging process again. A potential measuring means 18 for measuring the potential of the latent image formed on the photoconductor 16 by the above-mentioned exposure is arranged to face the surface of the photoconductor 16. The latent image potential data from the potential measuring means 18 is input to the CPU 4.

The CPU 4 is connected to a ROM (read-only memory) 7 in which a program for controlling the operation of the illuminating device by controlling the components of the flash power supply 2 and a program for the copying operation are stored in advance. A random access memory (RAM) 8 for rewriting and storing the data of the illuminance of 1 is connected. A display 6 for performing various displays is also connected to the CPU 4. As the display 6, an LED (light emitting diode) display panel, an LCD (liquid crystal display panel), or the like can be used.

Next, the operation of the above-described embodiment will be described. When the power switch 14 is turned on, the AC power supply 3 is supplied to the flash power supply 2. The flash power supply 2 boosts and rectifies the AC power supply 3, converts it into a high-voltage DC power supply, and stores it in the capacitor 2a. CP
When the trigger signal is output from U4, the flash lamp 1 is triggered, the energy stored in the capacitor 2a is instantaneously discharged through the flash lamp 1, and the flash lamp 1 emits light. The energy stored in the capacitor 2a is released by the emission of the flash lamp 1, and its voltage becomes almost 0V. Therefore, the input signal from the charging voltage detecting means 5 for detecting the charging voltage of the capacitor 2a becomes 0V. When this voltage becomes 0 V after a certain time from the application of the trigger, the light emission is completed.

At this time, if the voltage of the capacitor 2a is constant, the discharge current flowing through the flash lamp 1 decreases as the impedance between the capacitor 2a and the flash lamp 1 increases, so that the flash lamp 1 emits light. The amount decreases. FIG. 5 shows the relationship between the impedance and the amount of emitted light. The light emission amount of the flash lamp 1 can be directly measured by the optical measuring means 15. As the optical measuring means 15, an illuminometer using a photodiode or the like can be used. The measuring means 15 feeds back the lamp illuminance data to the CPU 4,
U4 informs the flash power supply 2 that the lamp light quantity is decreasing. When the phenomenon described above, that is, the decrease in the amount of light emission appears, one of the causes is considered to be deterioration of the connection portion 9. However, as another cause, a decrease in light amount due to deterioration of the tube wall of the flash lamp 1 itself may be considered.

Therefore, the illuminance value is set to a certain value a in advance, and when the illuminance measured value by the optical measuring means 15 becomes equal to or less than the set value a, the following discharge program is executed. First, the capacitor 2a is charged in the flash power supply 2, and the charging is turned off when the charging voltage reaches a predetermined voltage V0. Next, the relay coil 12b is energized from the relay drive circuit 12 in response to a command from the CPU 4 to close the relay contact 10a, and the energy stored in the capacitor 2a is discharged via the discharge resistor 11 having a resistance value r0. At this time, the break contact 2b of the relay is turned off, and the discharge circuit including the contact 2b and the resistor r3 is open. If the connection portion 9 is normal, the charging voltage V of the capacitor 2a falls from V0 according to a time constant which is a product of the capacitance of the capacitor 2a and the resistance value of the discharging resistor 11, as shown by a solid line in FIG. The voltage at the point in time Ta when a certain time (capacitor discharge time) has elapsed becomes Va. Therefore, if the voltage at the point in time Ta at which a certain time has elapsed is Va, the CPU 4 causes the display 6 to display, for example, an error message such as "The connection is normal.

However, when the connection portion 9 starts to cause a connection failure, the descending curve changes as shown by a dashed line in FIG. More specifically, the degree of the decrease in the capacitor charging voltage V with the passage of time is small, and the voltage Va1 at the time Ta is higher than the voltage Va at the time Ta when the connection portion 9 is normal. . FIG. 4 shows an equivalent circuit at this time.
As shown in FIG. 4, when the connection portion 9 causes a connection failure, a resistance portion indicated by r1 and r2 is generated in the connection portion 9 in the path of the discharge current, and the resistance R of the discharge circuit is R = r0 + r1 +.
r2, and the discharge time constant increases. Therefore, Va <V
a1. Furthermore, the discharge time T and the capacitor charging voltage V when the socket or plug of the connection portion 9 is broken and the electrical connection is cut off, or when the socket and plug are not set and the connection portion 9 is open. Is shown by a broken line in FIG. The resistances r1 and r2 become high resistance, and when the predetermined time elapses Ta, the voltage V
Does not fall, and when the voltage at that time is Va2, Va
The relationship between V2, V0 and Va is V0 = Va2> Va. This state is the same even if either one of the discharge current paths in the connection portion 9 is open. Therefore, the CPU 4 causes the display 6 to display, for example, "connection section abnormality" as an error message.

As described above, when the illuminance of the flash lamp 1 is reduced, it is easily determined whether the illuminance is caused by the deterioration of the contact of the connecting portion 9 or the deterioration of the flash lamp 1 itself. be able to. Then, a message corresponding to each abnormal state is displayed on the display 6, and
By notifying the user and the maintenance worker, quick maintenance can be performed. If the illuminance setting value a is set to a value at which the degree of deterioration of the connection portion 9 is expected to be mild, a fatal trouble due to a failure of the connection portion 9, such as destruction of the connection portion 9, will not occur. .

The above operation is shown in FIG. The operation will be described again with reference to FIG. The numbers “600 to 614” in FIG. 6 indicate the operation steps. The power switch 14 is turned on in step 601 (hereinafter, steps are indicated only by numerals such as “601” and “701”), and the flash lamp 1 is
In step 603, the illuminance is measured by the optical measuring unit 15. At 604, it is determined whether or not the measured illuminance value is equal to or smaller than the set value a. If the measured illuminance value is not equal to or smaller than the set value a, it is determined that there is no abnormality in a normal operation. , Followed by a predetermined electrophotographic process. If it is determined in 604 that the measured illuminance value is equal to or smaller than the set value a, charging of the capacitor 2 a by the flash power supply 2 is started in 605. In step 606, the control waits until the charging voltage V reaches the predetermined setting voltage Vo.
The charge is turned off at 7, and then the discharge relay RA is turned on to discharge the energy stored in the capacitor 2a via the discharge circuit having the discharge resistor 11.

In step 609, the process waits for the time TR during which the relay RA is on to reach the aforementioned Ta.
At 10 the discharge relay RA is turned off, and at 611 it is determined whether the charging voltage V is lower than a preset value Va. If the charging voltage V is lower than Va, an error message 1 is displayed at 613, for example, the above-mentioned display such as "the connection is normal. If it is determined at 611 that the charging voltage V is higher than Va, then at 612 the error message 2
Is displayed, for example, as described above, for example, “abnormal connection part”.

In the embodiment shown in FIG. 2, a light emitting current limiting member 19 (generally an inductor) is inserted between the capacitor 2a and the connecting portion 9. Usually, the current limiting member 19 is used for the purpose of suppressing the emission current of the flash lamp 1. The current limiting member 19 has copper loss due to electrical resistance loss and iron loss due to magnetoresistance loss, and generates heat due to these losses. This heat value changes depending on the current value and the frequency, and the temperature changes according to the heat value. In the case of the lighting device as shown in the illustrated embodiment, since the light emission current frequency is substantially constant, the light emission current value and the temperature have a certain proportional relationship. When the illuminance of the flash lamp 1 is lower than a predetermined value a, it can be determined whether there is an abnormality in the connection unit 9 or the flash lamp 1. The reason is as follows. When the contact resistance of the connection portion 9 increases under a constant lamp voltage, the emission current is suppressed, and the temperature of the current limiting member 19 decreases. FIG. 10 shows this, and shows the relationship between the impedance between the condenser 2a and the lamp 1 and the temperature of the current limiting member 19 made of a reactor.

Further, the current value may change due to an abnormality of the lamp 1 itself, for example, a change in the gas pressure, and the temperature of the current limiting member 19 may decrease. Therefore, when the illuminance of the lamp 1 is lower than the predetermined value a, it can be determined that there is an abnormality in either the connection portion 9 or the flash lamp 1. Therefore, by performing the same operation as 605 to 614 shown in FIG. 6, it is possible to determine whether there is an abnormality in the connection unit 9 or in the flash lamp 1. That is, the detection signal from the temperature measuring means 17 is input to the CPU 4, and when the temperature data of the current limiting member 19 falls below a certain set value under the condition that the lamp voltage is constant, the relay RA is energized as described above. Close the relay contact 10a and connect the capacitor 2 through the resistor 11.
By checking the capacitor charging voltage V while discharging the stored energy of “a”, it is determined whether the connection portion 9 is defective or the flash lamp 1 is abnormal.

FIG. 7 shows the flow of this operation. As shown in FIG. 7, the power switch 14 is turned on at 701, the lamp 1 emits light at 702, and the temperature measurement unit 1 is turned at 703.
7, the temperature of the current limiting member 19 is measured. It is determined at 704 whether the measured temperature value is equal to or less than a preset value b, and if the measured temperature value is equal to or greater than the set value b, both the connection unit 9 and the flash lamp 1 can be determined to be normal. If so, the normal copying operation is continued. If the measured temperature value is equal to or smaller than the set value b, it is considered that the connection unit 9 or the flash lamp 1 is abnormal, and the process proceeds to the next step 705. However, Step 705 is the same as Steps 605 to 614 of the above-described embodiment shown in FIG. 6, and after charging the capacitor 2a to a predetermined voltage Vo, the discharge resistor 11
And discharge is stopped at time Ta, and depending on whether the charging voltage V of the capacitor 2a at that time is higher or lower than the above-mentioned predetermined voltage Va, it is an abnormality of the connection portion 9 or an abnormality of the flash lamp 1. Can be determined. If there is a problem with the light emission of the lamp 1 when the connection section 9 is in a normal connection state, the charging voltage V becomes lower than Va. If there is an abnormality in the connection section 9, the charging voltage V becomes higher than Va, so that an abnormality in the connection section 9 can be detected. At this time, the trigger signal from the CPU 4 to the flash power supply 2 is turned off, and the display 6 indicates that an error has occurred.
It would be better if the machine operation could be stopped.

In FIG. 2, in an optical unit such as a copying machine, the irradiation light from the flash lamp 1 is reflected by the original, and is uniformly charged by the charger 20.
6 is irradiated with the above-mentioned reflected light to be exposed, and an image identical to the image of the original is formed as a latent image. In this case, to determine how much the change in the light amount of the flash lamp 1 affects the image to be formed, the potential of the latent image on the photoconductor 16 is measured rather than measuring the amount of light from the lamp 1. This has the advantage that the measurement can be performed in a manner closer to the output image. The potential measuring means 18 of the photoreceptor 16 is connected to the CPU 4 like the optical measuring means 15 and the temperature measuring means 17 described above. In the case of a copying machine or the like, a surface voltmeter for measuring the surface potential of the photoreceptor 16 is used as a unit for measuring the image forming state. Therefore, the surface voltmeter is also used as the potential measuring unit 18. Or a device similar to a surface electrometer may be used. If the above-mentioned surface voltmeter is also used as the potential measuring means 18, cost and space can be saved.

Connection 9 between condenser 2a and lamp 1
When the lamp 1 is abnormal or when the lamp 1 itself is deteriorated or defective, the amount of light applied to the document surface decreases. Then, the value of the potential of the latent image formed on the surface of the photoreceptor 16 increases, and the developed image becomes dark as a whole and becomes a background stain image or the like. Capacitor 2a and lamp 1 due to connection 9 failure
FIG. 11 shows the relationship between the impedance and the latent image potential. As can be seen from FIG. 11, the potential of the latent image increases as the impedance increases due to an abnormality in the connection portion 9. At the time of measuring the latent image potential, the photosensitive member 16 is exposed using a reference original on which a reference pattern is written instead of a general original, and an image of the original is formed as a latent image. The reference pattern is preferably provided in the apparatus in advance. As described above, by utilizing the phenomenon that the latent image potential changes due to the change in the impedance between the capacitor 2a and the lamp 1, it is possible to determine whether the connection portion 9 or the flash lamp 1 has an abnormality. You can judge. This determination operation will be described below.

In FIG. 8, at 801 the power switch 14
Is turned on, and the charger 20 is turned on to charge the photosensitive member 16 at 802, and the lamp 1 is caused to emit light at 803 to form the image of the reference pattern as a latent image on the surface of the photosensitive member 16. At 804, the potential of the latent image formed on the photoconductor 16 is measured by the potential measuring means 18. At 805, it is determined whether or not the measured value of the latent image potential is equal to or larger than a predetermined set value c. If the measured value is equal to or smaller than the set value c, it can be determined that both the connection unit 9 and the flash lamp 1 are normal. Therefore, if the copying machine is used, normal copying operation is continued. If the measured value is higher than the set value c, the connection 9 or the flash lamp 1
Therefore, the process proceeds to the next step 806.
However, step 806 is the same as steps 605 to 614 of the above-described embodiment shown in FIG.
Is charged to a predetermined voltage Vo, then discharged through the discharge resistor 11 and stopped at time Ta. At this time, the charging voltage V of the capacitor 2a is changed to the above-described predetermined voltage Va.
It is possible to determine whether the connection portion 9 is abnormal or the flash lamp 1 is abnormal depending on whether it is higher or lower.

FIG. 9 shows a specific example of the light emitting operation in step 602 in FIG. 6, step 702 in FIG. 7, and step 803 in FIG. In FIG. 9, the CPU 4 outputs light emission voltage data to the flash power supply 2 as one of output data at 901, and outputs a charging signal from the CPU 4 to the flash power supply 2 at 902. In response to the charging signal, the flash power supply 2 starts charging the capacitor 2a (903). At 904, the charging is completed, and at 905, a charging completion signal is output from the flash power supply 2 to the CPU 4. At 906, a light emission trigger signal is output from the CPU 4 to the flash power supply 2, and the trigger signal causes a light emission operation to be performed at 907. This light emitting operation is a light emitting operation for performing the original function of the apparatus such as a copying machine and a facsimile,
Thus, copying of the document image, transmission of the document image, and the like are performed.

[0033]

According to the first aspect of the present invention, in the lighting device having a connecting portion for connecting the condenser and the lamp by causing the flash lamp to emit light with the luminous energy stored in the capacitor. A discharge resistor connected in parallel with the lamp on the lamp side, switching means connected in series to the discharge resistance, and an optical measurement means for measuring the lamp illuminance, and the lamp measured by the optical measurement means When the light emission illuminance becomes equal to or less than the set value, the opening / closing means is closed to form a capacitor discharge circuit using a discharge resistor, and the capacitor voltage after the start of discharge is detected by the charge voltage detection means. Depending on whether the capacitor voltage after the start of the discharge detected at the time is equal to or less than a preset value, the connection of the connection portion is abnormal. Or it is possible to detect whether the other abnormalities. This makes it easier to detect deterioration with time of the connection between the socket and the plug of the connection portion, and can prevent damage to the socket and the plug beforehand. Something can be easily identified.

According to the second aspect of the present invention, in the lighting device having a connecting portion for connecting the condenser and the lamp by causing the flash lamp to emit light with the luminous energy stored in the condenser, A discharge resistor connected in parallel to the lamp on the lamp side; switching means connected in series to the discharge resistor; a current limiting member provided between the capacitor and the connection portion; and a temperature of the current limiting member. When the temperature of the current limiting member measured by the temperature measuring means falls below a certain temperature, the opening and closing means is closed to form a capacitor discharge circuit by a discharge resistor, Since the capacitor voltage after the start of discharging is detected by the charging voltage detecting means, the temperature of the current limiting member measured by the temperature measuring means is measured. Advance by the value set less is or country can detect whether the said connection portion of the connection abnormality as or other abnormalities. This makes it easier to detect deterioration with time of the connection between the socket and the plug of the connection portion, and can prevent damage to the socket and the plug beforehand. Something can be easily identified.

According to the third aspect of the present invention, the flash lamp is caused to emit light by the luminous energy stored in the condenser, and the connection portion connecting the condenser and the lamp, and the latent image of the original image illuminated by the flash lamp is formed. In a lighting device of an image forming apparatus having a photosensitive member to be formed, a discharge resistor connected in parallel with the lamp on the lamp side with respect to the connection portion, and an opening / closing unit connected in series to the discharge resistor. A potential measuring means for measuring the potential of the latent image on the photoreceptor, and when the potential value of the latent image measured by the potential measuring means exceeds a certain set value, the opening / closing means is closed to discharge the capacitor by the discharge resistor. Since a circuit is formed and the capacitor voltage after the start of discharging is detected by the charging voltage detecting means, the latent image potential value measured by the potential measuring means Depending on whether a certain set value or country can detect whether or other anomalies are abnormal connection of the connecting portion. This makes it easier to detect deterioration with time of the connection between the socket and the plug of the connection portion, and can prevent damage to the socket and the plug beforehand. Something can be easily identified.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an embodiment of a lighting device according to the present invention.

FIG. 2 is a partial cross-sectional side view showing an example of a connection portion applicable to the present invention.

FIG. 3 is a graph showing a relationship between a discharge time and a voltage of a capacitor in a case where a connection portion is normal and in a case where the connection portion is abnormal in the embodiment.

FIG. 4 is an equivalent circuit diagram showing a case in which a discharge circuit for a capacitor is formed via a connection in the above embodiment.

FIG. 5 is a graph showing the relationship between the impedance between the condenser and the flash lamp and the amount of emitted light in the embodiment.

FIG. 6 is a flowchart showing an operation example of the embodiment.

FIG. 7 is a flowchart showing another operation example of the embodiment.

FIG. 8 is a flowchart showing still another operation example of the embodiment.

FIG. 9 is a flowchart showing a light emitting operation in FIGS. 6, 7, and 8;

FIG. 10 is a graph showing a relationship between the impedance between the condenser and the flash lamp and the temperature of the reactor as the current limiting member in the embodiment.

FIG. 11 is a graph showing a relationship between an impedance between a condenser and a flash lamp and a potential of a latent image formed on a photoconductor in the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flash lamp 2a Capacitor 5 Charge voltage detecting means 9 Connecting part 10a Opening / closing means 11 Discharge resistance 15 Optical measuring means 16 Photoreceptor 17 Temperature measuring means 18 Potential measuring means 19 Current limiting member

Claims (3)

[Claims] 1. A flash lamp, a capacitor for storing luminous energy of the flash lamp, and charging voltage detecting means for detecting a charging voltage of the capacitor;
In a lighting device having a connection portion for connecting the capacitor and the lamp, a discharge resistor connected in parallel with the lamp on the lamp side with respect to the connection portion, and switching means connected in series to the discharge resistor. An optical measuring means for measuring the lamp light emission illuminance, wherein when the lamp light emission illuminance measured by the optical measurement means becomes equal to or less than a set value, the opening / closing means is closed to discharge the capacitor discharge circuit by the discharge resistor. A lighting device characterized in that a capacitor voltage after the start of discharging is detected by the charging voltage detecting means. 2. A flash lamp, a capacitor for storing luminous energy of the flash lamp, and charging voltage detecting means for detecting a charging voltage of the capacitor;
In a lighting device having a connection portion for connecting the capacitor and the lamp, a discharge resistor connected in parallel with the lamp on the lamp side with respect to the connection portion, and switching means connected in series to the discharge resistor. A current limiting member provided between the capacitor and the connection portion; and a temperature measuring means for measuring the temperature of the current limiting member, wherein the temperature of the current limiting member measured by the temperature measuring means is constant. When the temperature falls below the temperature, the switching means is closed to form a discharge circuit of the capacitor by the discharge resistor, and the capacitor voltage after the start of discharge is detected by the charge voltage detection means. 3. A flash lamp, a capacitor for storing luminous energy of the flash lamp, and charging voltage detecting means for detecting a charging voltage of the capacitor;
A lighting device for an image forming apparatus, comprising: a connecting portion for connecting the condenser and the lamp; and a photoconductor on which a latent image of a document image illuminated by the flash lamp is formed. A discharge resistor connected in parallel with the lamp, switching means connected in series to the discharge resistor, and potential measuring means for measuring a latent image potential on the photoreceptor, which is measured by the potential measuring means. When the latent image potential value exceeds a certain set value, the opening / closing means is closed to form a discharge circuit of the capacitor by the discharge resistor, and the capacitor voltage after the start of discharge is detected by the charge voltage detection means. A lighting device characterized by the above-mentioned.