JPH05188745A - Exposure adjusting device for electrophotographic device - Google Patents

Abstract

PURPOSE:To recognize application for judging whether the operating state of a light source is normal or not by deciding whether a detection value when the quantity of light reflected from a standard reflecting plate is detected, is larger than a normal threshold value or not. CONSTITUTION:In adjustment for exposing, when the detection value of a surface potential sensor 51 as a surface state detecting means is not normal, continuously, a master CPU 40 as a light source light quantity discriminating means, irradiates a standard white sheet with the light in a state where a prescribed voltage is applied on a copy lamp 3, and decides whether the detection value when the quantity of the light reflected from the standard white sheet is detected by an AE sensor 52, is larger than the normal threshold or not. Therefore, it can be recognized that the operating state of the copy lamp 3 is normal or not. Thus, at the time of occurrence of a failure, it is clear that the factor of the failure has something to do with the light source or not, an efficient countermeasure can be attained, and a period in a failure state is shortened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is provided in an electrophotographic apparatus such as a copying machine, and the exposure of the electrophotographic apparatus is controlled by controlling the light amount of the light source and the charging potential of the photoconductor to optimum values. It relates to an adjusting device.

[0002]

2. Description of the Related Art Generally, in a copying machine as an electrophotographic apparatus, for example, a photoconductor pre-charged by a charger is exposed by reflected light from a document optically scanned by a light source, whereby the photoconductor is exposed. An electrostatic latent image is formed, and the electrostatic latent image is developed and visualized to obtain a copy image.

Some of the above copying machines are provided with an exposure adjusting device for adjusting the exposure by controlling the light amount of the light source and the charging potential of the photoconductor to the optimum values. In such a copying machine, as shown in FIG. 2 which is an explanatory view of the present invention, a surface potential sensor 51 as a surface state detecting means is provided on the developing unit 23 side of the exposure position of the photoconductor 21, Prior to the optical scanning of the original, the standard white plate 53 with the copy lamp 3
The surface potential sensor 51 detects the surface potential of the portion of the photoconductor 21 exposed by the reflected light from the standard white plate 53.

As shown in FIG. 9, the surface potential sensor 51 controls the exposure adjustment of the conventional exposure adjusting apparatus.
If the output is within the lower limit of normal potential C'to the upper limit of normal potential D ', it is judged to be within the normal range in which exposure control is possible and adjusted to the optimum value K'. If the upper limit D ′ or more, it is determined that all are in failure.

That is, in the exposure adjustment control of the control unit, as shown in FIG. 10, when the copy start key is turned on (S1), a predetermined voltage is applied before the optical scanning of the original. The standard white plate 53 is illuminated by the copy lamp 3 (S2), and the surface potential of the photoconductor 21 in the portion exposed by the reflected light from the standard white plate 53 is detected by the surface potential sensor 51. At this time, the surface potential sensor 5
It is determined whether or not the output of No. 1 is the normal potential lower limit C'to the normal potential upper limit D '(S3), and if the output of the surface potential sensor 51 is the normal potential lower limit C'to the normal potential upper limit D', then Then, it is determined whether or not the output of the surface potential sensor 51 is the optimum value K '(S4). Then, if the optimum value K ′ is obtained in S4, the copy process is started to obtain a copy image (S5). Further, in S4, the surface potential sensor 5
If the output of 1 is not the optimum value K ', the surface potential sensor 51
Is larger than the optimum value K '(S)
6) If it is larger than the optimum value K ′, the light quantity of the copy lamp 3 is increased and the applied voltage applied to the charger 22 is controlled so as not to cause the image quality fog (S7), while the optimum value is controlled. If the value is smaller than the value K ', the light quantity of the copy lamp 3 is reduced and the applied voltage applied to the charger 22 is increased (S8) so as not to reduce the image density. On the other hand, if the output of the surface potential sensor 51 is not within the range of the potential normal lower limit C'to the potential normal upper limit D'in S3, the surface potential sensor failure is displayed.

On the other hand, a copy lamp 3 used in a copying machine
As shown in FIG. 4 which is an explanatory view of the present invention, the lighting state is divided into a lamp normal range, a lamp dark range and a lamp burnout range, and the lamp is normally lit in the normal lamp range. However, when the copy lamp 3 becomes fatigued due to its life, the copy lamp 3 is in a lamp dark range in which it does not reach a predetermined light amount even if the rated voltage is applied. In this lamp dark range, the voltage applied to the copy lamp 3 is reduced. The amount of light can be increased by increasing the amount. It should be noted that when the copy lamp is burnt out or is in a state close to that, the lamp burnout range is set.

[0007]

However, in the exposure adjusting apparatus of the above-mentioned conventional electrophotographic apparatus, when the output of the surface potential sensor 51 is not between the potential lower limit C'and the potential upper limit D ', the cause may be any cause. Even if that is,
For example, in the case where the light quantity of the copy lamp 3 is reduced but the output is increased by a manual operation, the detection value of the surface potential sensor 51 can be set between the normal potential lower limit C ′ and the potential normal upper limit D ′. Also prohibits the copying process, displays a surface potential sensor failure indication, and prompts a service person to repair it. In addition, it takes time to understand the cause of failure during repair, and the copying machine cannot be used during that time.

The present invention has been made in view of the above conventional problems, and an object thereof is to make it possible to check whether the applied voltage applied to the light source and the charger 22 of the photoconductor is normal. An object of the present invention is to provide an exposure adjustment device for an electrophotographic apparatus, which enables a failure factor to be identified and efficiently dealt with in the event of a failure, and which can shorten the period of the failure state.

[0009]

In order to solve the above-mentioned problems, an exposure adjusting apparatus for an electrophotographic apparatus according to a first aspect of the present invention uses a reflected light from a document optically scanned by a light source to cause a charging device. The pre-charged photoconductor is exposed to light, an electrostatic latent image is formed on the photoconductor, and the electrostatic latent image is developed and visualized. Before, irradiate the standard reflection plate with the light source, and detect the surface state of the photoconductor exposed by the reflected light from the standard reflection plate with the surface state detection means, when the detected value is within the normal range, In the exposure adjusting device of the electrophotographic apparatus for controlling the exposure by controlling the light amount of the light source and the charging potential of the photoconductor to the optimum value, the light amount detecting means for detecting the amount of reflected light from the standard reflection plate is provided, Applying a predetermined voltage to the light source In the state, the standard reflection plate is irradiated with light, and the light source light amount determination means for determining whether or not the detection value when the amount of light reflected from the standard reflection plate is detected by the light amount detection means is larger than the normal limit value. Is provided.

In order to solve the above-mentioned problems, an exposure adjusting device of an electrophotographic apparatus according to a second aspect of the present invention is a photosensitive member precharged by a charger by reflected light from a document optically scanned by a light source. The body is exposed, an electrostatic latent image is formed on the photoreceptor by this, and the electrostatic latent image is developed and provided in an electrophotographic apparatus that is visualized, and before the optical scanning of the document,
Irradiate the standard reflection plate with the light source, and detect the surface state of the photoconductor exposed by the reflected light from the standard reflection plate with the surface state detection means, and when the detected value is within the normal range,
In an exposure adjusting device of an electrophotographic apparatus that controls the exposure by controlling the light amount of a light source and the charging potential of a photoconductor to an optimum value, the applied voltage when a predetermined voltage is applied to the charger is within a normal range. It is characterized in that an applied voltage determining means for determining whether or not it is provided.

[0011]

According to the structure of the present invention, the light source light amount discriminating means irradiates the standard reflecting plate with light while a predetermined voltage is applied to the light source, and the quantity of light reflected from the standard reflecting plate is detected by the light amount detecting means. It is determined whether or not the detected value when detected in step 1 is larger than the normal limit value.

Therefore, the operating state of the light source is determined by the value detected when the light amount detecting means detects the amount of reflected light when the above-mentioned light source is turned on at a predetermined voltage and the standard reflector is illuminated by this light source. It is possible to know whether it is normal or not. As a result, at the time of a failure, it becomes clear whether or not the failure factor is related to the light source, so that it is possible to efficiently deal with it.

According to the second aspect of the invention, the applied voltage determining means determines whether the applied voltage when the predetermined voltage is applied to the charger is within the normal range.

Therefore, it is possible to know whether the operating state of the charger is normal. As a result, when a failure occurs, it becomes clear whether or not the failure factor is related to the charger, so that it is possible to efficiently deal with it.

[0015]

【Example】

[Embodiment 1] FIG. 1 through FIG.
The explanation is based on the following.

As shown in FIG. 2, a copying machine as an electrophotographic apparatus of the present embodiment has an optical system 2 on the top of a copying machine main body 1.
Are arranged. The optical system 2 includes, for example, a copy lamp 3 including a halogen lamp and a plurality of mirrors 4 to 7.
And a zoom lens 8.

A photoconductor 21 is rotatably supported below the optical system 2. Around the photoconductor 21, a charger 22, a developing unit 23, a transfer unit 24, a charge eliminator 25 and the like are provided. It is distributed.

In the paper feed direction with respect to the transfer device 24, there are provided a paper feed section 30 and a registration roller 31 in which paper feed cassettes of different sizes are arranged one above the other, while the transfer device 24 conveys paper in the paper delivery direction. An apparatus 32, a fixing unit 33 for thermally fixing the toner on the transfer paper to the transfer paper, a paper transport path 35, and a discharge tray 34 are provided.

The paper transport path 35 includes an intermediate tray 36,
The reversing unit 37 and the paper feed roller 38 are provided so that the transfer paper is conveyed in the paper feed direction of the transfer device 24 at the time of composite copying or double-sided copying.

Further, in the present copying machine, an automatic document feeder 27 is arranged above the copying machine main body 1. The automatic document feeder 27 includes a document transport path 28 and drums 29a and 29b provided in the document transport path 28. The document is automatically fed and the front and back sides of the document are reversed to copy the back side. It is possible to make a composite copy or an automatic copy in a double-sided copy.

Further, the copying machine of this embodiment uses AE (A) as a light amount detecting means for detecting the reflected light from the copy lamp 3.
Utomatic Exposure) sensor 52, a surface potential sensor 51 as a surface state detecting means for detecting the surface potential of the photoconductor 21, the AE sensor 52 and the surface potential sensor 51.
And a standard white plate 53 used in the detection by. The AE sensor 52 is provided below the copy lamp 3 so as to detect the amount of light reflected from the standard white plate 53. The AE sensor 52 and the mirror 4 move together with the copy lamp 3 when the copy lamp 3 optically scans the original. Further, the standard white plate 53 is arranged at a position outside the upper original area in the copying machine main body 1, and this position is also above the home position of the copy lamp 3. The surface potential sensor 51 is provided on the side of the developing unit 23 at the exposure position of the photoconductor 21 and detects the surface potential of the exposed portion of the photoconductor 21.

On the other hand, as shown in FIG. 3, the control section of the copying machine is a master CPU (Master Central Processing Unit) 4 for controlling the formation of an electrostatic latent image on the photoconductor 21.
0 and a slave CPU (Slave CP) that controls the optical system 2.
U) 41.

The master CPU 40 includes the slave CPU 41, a ROM (Read Only Memory) 42, a copy lamp lighting circuit 43 for the copy lamp 3, a charging unit 50 for the charger 22, a surface potential sensor 51 and an AE sensor 52. Are connected.

The ROM 42 stores various programs for operating the copying machine, and sets a plurality of combination values of the voltage applied to the copy lamp 3 and the voltage applied to the photosensitive member 21 as a preset value. I remember.

The AE sensor 52 receives the reflected light from the standard white plate 53 when the copy white lamp 3 is illuminated by applying a predetermined voltage to the copy lamp 3, and outputs an output signal to the master CPU 40. It is like this.

Then, the master CPU 40 serves as a light source light amount discriminating means, as shown in FIG.
If the output of 2 is equal to or more than the light amount normal limit value A shown in the figure,
It is determined that the light quantity of the copy lamp 3 is normal, and if it is between the light quantity normal limit value A and the light quantity correction limit value B, it is judged that the copy lamp 3 has decreased in light quantity due to fatigue, and the light quantity correction limit value B If it is below, it is determined that the copy lamp 3 is off.

The surface potential sensor 51 is a standard white plate 53.
The surface potential of the photoconductor 21 exposed by the reflected light from is detected to output an output signal to the master CPU 40. That is, the master CPU 40
Is a surface potential sensor that irradiates the standard white plate 53 with the copy lamp 3 before the optical scanning of the original and exposes the photoconductor 21 with the reflected light from the standard white plate 53. The detection is performed at 51. Then, as shown in FIG. 5, if the detected value of the surface potential sensor 51 is in the range of the normal potential lower limit C to the normal potential upper limit D (normal range), it is determined to be a normal range in which exposure control is possible, If the output of the potential sensor 51 is in the range of the potential correction lower limit E to the potential normal lower limit C or the potential normal upper limit D to the potential correction upper limit F, it is determined to be outside the exposure control range, and the output of the surface potential sensor 51 is the potential. If the correction lower limit E or less, or the potential correction upper limit F or more, it is determined that the failure. Further, when the detected value of the surface potential sensor 51 is the normal potential lower limit C to the potential normal upper limit D (normal range), the light amount of the copy lamp 3 and the charged potential of the photoconductor 21 are controlled to the optimum value K. It is designed to adjust the exposure.

Further, the master CPU 40 adjusts the effective voltage level applied to the copy lamp 3 via the copy lamp lighting circuit 43 and supplies various high voltage units such as a charging unit 50 for supplying a high voltage to the charger 22. Is controlled.

The charger 22 is provided with a grid 22a as shown in FIG. 6 which is an explanatory view of the second embodiment.
By 2b, a constant voltage is applied to the charger 22.

Further, the master CPU 40 receives signals from various keys and sensors, and the slave CPU 4
A signal for returning the mirror 4 to the home position, a signal for returning the mirror 4 which has finished moving in the X direction to the home position, and the like are transmitted to the terminal 1.

The slave CPU 41 receives a signal from a rotary encoder 45 for detecting the rotation speed of the motor 18 and a signal from a home position sensor (not shown) according to a program stored in advance in the ROM 44, and via a driver 46. It plays the role of controlling the rotation speed of the motor 18 and transmitting a signal for instructing the registration roller 31 when to supply the paper to the photoconductor 21.

The copy operation of the copying machine of the present embodiment having the above-mentioned structure will be described below with reference to the flow chart of FIG. 1 and FIG.

First, as shown in FIG. 1, when a copy start key provided in an operation section (not shown) provided in the main body 1 of the copying machine is turned on (S1), a predetermined voltage is applied to the copy lamp 3 to make a copy. Lamp 3 lights up. At this time, the copy lamp 3 is located at the home position where the standard white plate 53 is arranged and illuminates the standard white plate 53 (S
2). Then, the surface potential of the photoconductor 21 exposed by the reflected light from the standard white plate 53 is the surface potential sensor 51.
Detected at. Then, it is determined whether or not the output of the surface potential sensor 51 is within the lower limit of normal potential C to the upper limit of normal potential D (S3). If the output is within the range of lower limit of normal potential C to upper limit of normal potential D, the surface potential sensor is detected. It is determined whether or not the output of 51 is the optimum value K (S4).

If the output of the surface potential sensor 51 is the optimum value K in S4, the copy process described later is started to obtain a copy image (S5). If the output of the surface potential sensor 51 is not the optimum value K in S4, the output of the surface potential sensor 51 is the optimum value K.
It is determined whether or not it is larger than (S6). If the output of the surface potential sensor 51 is larger than the optimum value K in S6, the light quantity of the copy lamp is increased and the applied voltage applied to the charger 22 is decreased so as not to cause image quality fog (S7), and the process returns to S4. .. Further, in S6, the surface potential sensor 5
If the output of 1 is smaller than the optimum value K, the light quantity of the copy lamp is decreased and the applied voltage applied to the charger 22 is increased so that the image density is not reduced (S8), and S
Return to 4. The process up to this point is the same as the conventional exposure adjustment.

Next, in the exposure adjusting apparatus of the present embodiment, the output of the surface potential sensor 51 is the lower limit of normal potential C at S3.
~ If not within the range of the normal potential upper limit D, the AE sensor 52
Thus, the amount of light reflected from the standard white plate 53 is detected.
Then, it is judged whether or not the detection value of the AE sensor 52 is equal to or more than the light amount normal limit value A (S9). If the detection value is equal to or more than the light amount normal limit value A, for example, a "surface potential sensor" is displayed on the operation unit. "Failure" is displayed (S10). Also,
When the detected value of the AE sensor 52 is not equal to or more than the light amount normal limit value A in S9, it is determined whether the detected value of the AE sensor 52 is the light amount correction limit value B or more (S11). A at S11
When the detection value of the E sensor 52 is equal to or more than the light amount correction limit value B, "Lamp Dark" is displayed on the operation unit (S12). By this display, it is possible to perform exposure adjustment according to a preset value stored in the ROM 42 by operating a manual exposure adjustment key provided on an operation unit (not shown).

If the detection value of the AE sensor 52 is not equal to or more than the light amount correction limit value B in S11, "lamp out" is displayed on the operation unit (S13).

Here, the copying process (S14) by optical scanning of the original will be described. First, at the time of copying, as shown in FIG. 2, while the surface of the photoconductor 21 is charged to a predetermined potential by the charger 22, an original document (not shown) covered by the original document cover 26 is replaced by the copy lamp 3 As the mirror 4 and the AE sensor 52 move in the X direction, the copy lamp 3 sequentially irradiates the front end of the document and optically scans it. Then, the reflected light from the document is exposed on the photoconductor 21 via the optical system 2, so that an electrostatic latent image is formed on the photoconductor 21.

On the other hand, when copying is performed using the automatic document feeder 27 arranged above the copying machine main body 1, the document is drums 29a and 29b in the document feeding path 28 of the automatic document feeder 27. Is conveyed by the document conveying path 28.
The copy lamp 3 sequentially irradiates from the tip through slits (not shown) provided at two positions. Then, in the same manner as described above, the reflected light from the document is exposed to the photoconductor 21 and an electrostatic latent image is formed on the photoconductor 21.

Next, the electrostatic latent image is developed with toner supplied from the developing section 23 to form a toner image. After that, a sheet (not shown) is sent to the registration roller 31 from the sheet feeding unit 30 having a plurality of sheet feeding cassettes, and this sheet is
After being stopped once by the registration roller 31 as needed, it is supplied to the transfer device 24 at a predetermined timing.
Then, the toner image is transferred by the transfer device 24 onto the supplied paper.

After that, the paper is peeled off from the photosensitive member 21, conveyed to the fixing unit 33 by the conveying device 32, and the toner image is fixed thereon. In the case of one-sided copying, the paper is ejected to the ejection tray 34 as it is. .. On the other hand, in the case of synthetic copying or double-sided copying, the sheet discharged from the fixing unit 33 is sent to the sheet conveying path 35, and in the case of synthetic copying, it is discharged as it is to the intermediate tray 36, while in the case of double-sided copying, After being turned upside down by the turnover unit 37, the sheet is carried out to the intermediate tray 36. When a predetermined number of sheets are accumulated in the intermediate tray 36, the sheets on the intermediate tray 36 are sequentially fed from the uppermost one by the sheet feeding roller 38, and the transfer device 2
No. 4 is sent, and copying is continuously performed.

As described above, in the copying machine of the present embodiment, in the exposure adjustment, when the detected value of the surface potential sensor 51 as the surface state detecting means is not normal, the master CPU 40 as the light source light amount determining means continues. But,
Is the detected value when the standard white plate 53 is irradiated with light with the predetermined voltage applied to the copy lamp 3 and the amount of light reflected from the standard white plate 53 is detected by the AE sensor 52 is larger than the normal limit value? Since it is determined whether or not, immediately
It is possible to know whether the operating state of the copy lamp 3 is normal. As a result, at the time of a failure, it becomes clear whether or not the failure factor is related to the light source, so that it is possible to efficiently deal with the problem, and it is possible to shorten the period of the failure state.

In the exposure adjusting apparatus of this embodiment, when the detection value of the surface state detecting means is not normal, the light quantity of the copy lamp 3 is automatically checked subsequently. However, it is not necessarily limited to this. That is, for example, the light amount of the copy lamp 3 can be inspected at any time by operating the manual switch provided in the operation unit.

In the present embodiment, the surface potential sensor 5 for detecting the surface potential of the photoconductor 21 is used as the surface state detecting means.
However, the number is not necessarily limited to this. That is, as the surface state detecting means, it is also possible to adopt an optical sensor including a light emitting portion and a light receiving portion for detecting the density of the toner amount formed on the photoconductor to adjust the exposure.

[Embodiment 2] The following will describe another embodiment of the present invention with reference to FIGS. 6 to 8. For convenience of explanation, members having the same functions as those shown in the drawings of the first embodiment will be designated by the same reference numerals, and the description thereof will be omitted.

The exposure adjusting apparatus of the copying machine of this embodiment is shown in FIG.
As shown in FIG. 5, the charging unit 50 is connected to the charging device 22, and the charging unit 50 and the charging device 22 are provided with a resistor R1 and a resistor R2 that are arranged in series and branched. .. A terminal 22c is provided between the resistors R1 and R2, and the charging unit 50
It is possible to output the divided voltage of the high voltage supplied from. In addition, the reason why the divided voltage can be output is that the voltage applied to the charger 22 is a high voltage, and therefore the voltage is reduced at the time of detection. Therefore, it is not always necessary to detect the divided voltage of the applied voltage when the predetermined voltage is applied to the charger 22, and it is also possible to detect the voltage of the grid 22a of the charger 22 by resistance division.

On the other hand, the master CPU 40, as an applied voltage determining means, determines whether or not the divided voltage value of the applied voltage when the predetermined voltage is applied to the charger 22 is within the normal range. There is. That is, as shown in FIG. 7, if the divided voltage value is in the range of the voltage normal lower limit value G to the voltage normal upper limit value H, it is determined to be normal and whether the divided voltage value is larger than the voltage normal upper limit value H. Alternatively, if it is smaller than the voltage normal lower limit value G, it is determined as a failure.

The copying operation of the copying machine of this embodiment having the above-mentioned structure will be described below with reference to the flow chart of FIG. In addition, in S3 shown in this flowchart,
When the output of the surface potential sensor 51 is within the range of the potential lower limit C to the potential upper limit D, the process is the same as the flowchart of FIG.

That is, in the present embodiment, as shown in FIG. 8, when the output of the surface potential sensor 51 is not within the range from the lower limit potential C to the upper limit potential normal D in S3, it serves as the applied voltage determining means. The divided voltage value to the charger 22 is detected by the master CPU 40 (S21). Then, it is determined whether or not this divided voltage value is in the range of the voltage normal lower limit value G to the voltage normal upper limit value H (S22). If the divided voltage value is in the range of the voltage normal lower limit value G to the voltage normal upper limit value H in S22, for example, "surface potential sensor failure" is displayed on the operation unit (S23). If the divided voltage value is within the range of the voltage normal lower limit value G to the voltage normal upper limit value H in S22, for example, "charger failure" is displayed on the operation unit (S24).

As described above, the exposure adjusting apparatus of the copying machine of this embodiment has the surface potential sensor 51 as the surface state detecting means.
When the detected value of is not normal, subsequently, the master CPU 40 as the applied voltage determination means determines whether the divided voltage value of the applied voltage when the predetermined voltage is applied to the charger 22 is within the normal range. Therefore, immediately, the charger 22
It is possible to grasp whether or not the operating state of is normal. As a result, at the time of a failure, it becomes clear whether or not the failure factor is related to the charger, so that it is possible to efficiently deal with it, and in turn, it is possible to shorten the period of the failure state.

In the exposure adjusting apparatus of this embodiment, the voltage applied to the charger 22 is automatically inspected when the detected value of the surface state detecting means is not normal. However, it is not necessarily limited to this. That is, for example, by operating a manual switch provided in the operation unit, it is possible to inspect the light amount of the voltage applied to the charger 22 at any time.

[0051]

As described above, the exposure adjusting device of the electrophotographic apparatus according to the first aspect of the present invention is provided with the light amount detecting means for detecting the amount of light reflected from the standard reflection plate and applies a predetermined voltage to the light source. In this state, the standard reflection plate is irradiated with light, and it is determined whether or not the detection value when the amount of light reflected from the standard reflection plate is detected by the light amount detection means is larger than the normal limit value. Means are provided.

As a result, the operating state of the light source is determined by detecting the amount of reflected light when the above-mentioned light source is turned on at a predetermined voltage and the standard reflection plate is illuminated by this light source by the light amount detecting means. It is possible to know whether it is normal or not. As a result, at the time of failure, it becomes clear whether or not the failure factor is related to the light source, so that it is possible to efficiently deal with it, and in turn, it is possible to shorten the period of the failure state.

In the exposure adjusting device of the electrophotographic apparatus according to the second aspect of the present invention, as described above, it is determined whether the applied voltage when the predetermined voltage is applied to the charger is within the normal range. It is a configuration in which an applied voltage determining means for performing the operation is provided.

As a result, it is possible to know whether or not the operating state of the charger is normal. As a result, in case of failure,
Since it becomes clear whether or not the failure factor is related to the charger, it is possible to efficiently deal with the problem, and thus it is possible to shorten the period of the failure state.

[Brief description of drawings]

FIG. 1 is a flow chart showing a control when exposure adjustment is performed by an exposure adjustment device of an electrophotographic apparatus according to an embodiment of the present invention.

FIG. 2 is an overall configuration diagram showing a copying machine provided with the exposure adjustment device.

FIG. 3 is a block diagram showing a control unit in the exposure adjustment apparatus.

FIG. 4 is a graph showing a relationship between an AE sensor output and a lighting state of a copy lamp in the exposure adjusting apparatus.

FIG. 5 is a graph showing the relationship between the surface potential sensor output and the exposure state of the photoconductor in the exposure adjustment apparatus.

FIG. 6 is an explanatory diagram showing a configuration for outputting a divided voltage of a voltage applied to a charger in an exposure adjustment device of an electrophotographic apparatus according to another embodiment of the present invention.

FIG. 7 is a graph showing a relationship between a charging device division voltage value and a charging state in the exposure adjusting apparatus.

FIG. 8 is a flow chart showing control in the case where exposure adjustment is performed by the exposure adjustment apparatus.

FIG. 9 is a graph showing a conventional example and showing a relationship between an output of a surface potential sensor and an exposure state of a photoconductor in an exposure adjustment device of a copying machine.

FIG. 10 is a flow chart showing a control in the exposure adjustment device of the copying machine when the exposure adjustment is performed by controlling the light amount of the copy lamp and the charging potential of the photoconductor by detecting the surface potential of the photoconductor.

[Explanation of symbols]

3 Copy Lamp (Light Source) 21 Photoreceptor 22 Charger 22a Grid 22c Terminal 23 Developing Unit 40 Master CPU (Light Source Light Amount Discriminating Means, Applied Voltage Discriminating Means) 51 Surface Potential Sensor (Surface Condition Detecting Means) 52 AE Sensor (Light Amount Detecting Means) ) 53 Standard white plate (standard reflector) A Light intensity normal limit value B Light intensity correction limit value C Potential normal lower limit D Potential normal upper limit E Potential correction lower limit F Potential correction upper limit G Voltage normal lower limit value H Voltage normal upper limit value K Optimal value R1 Resistance R2 resistance

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shigeo Kusumoto 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka Within Sharp Corporation (72) Inventor Jun Morimoto 22-22 Nagaike-cho, Abeno-ku, Osaka, Osaka Within the corporation

Claims (2)

[Claims] 1. A photoreceptor pre-charged by a charger is exposed by reflected light from a document optically scanned by a light source, whereby an electrostatic latent image is formed on the photoreceptor, and the electrostatic latent image is formed. Is provided in an electrophotographic apparatus which is developed and visualized, and before the optical scanning of the above-mentioned original, irradiates a standard reflection plate with a light source,
The surface state of the photoconductor exposed by the reflected light from the standard reflection plate is detected by the surface state detection means, and when the detected value is within the normal range, the light amount of the light source and the charging potential of the photoconductor become the optimum values. In the exposure adjusting device of the electrophotographic apparatus for controlling and adjusting the exposure so that the light amount detecting means for detecting the amount of light reflected from the standard reflecting plate is provided, and the standard reflecting plate is applied with a predetermined voltage applied to the light source. A light source light amount determination means for determining whether or not the detected value when the amount of light reflected from the standard reflection plate is detected by the light amount detection means is larger than the normal limit value is provided. An exposure adjustment device for an electrophotographic apparatus. 2. A photoconductor pre-charged by a charger is exposed by reflected light from a document optically scanned by a light source, whereby an electrostatic latent image is formed on the photoconductor, and the electrostatic latent image is formed. Is provided in an electrophotographic apparatus which is developed and visualized, and before the optical scanning of the above-mentioned original, irradiates a standard reflection plate with a light source,
The surface state of the photoconductor exposed by the reflected light from the standard reflection plate is detected by the surface state detection means, and when the detected value is within the normal range, the light amount of the light source and the charging potential of the photoconductor become the optimum values. In the exposure adjusting device of the electrophotographic apparatus for controlling the exposure so as to adjust the applied voltage, the applied voltage determining means for determining whether or not the applied voltage when the predetermined voltage is applied to the charger is within the normal range is provided. An exposure adjustment device for an electrophotographic apparatus, which is characterized in that