JP2003316217A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming device which, for an automatic regulation of the light quantity of an optical sensor, judges whether the lowering of the light quantity is caused by element deterioration, or the lowering of the light quantity is caused by an installation error, fouling or the like by setting the threshold of an input voltage appropriately at adjustment time; which processes it according to the judgement so that it works advantageously in terms of the lifetime of the element with a longer interval of maintenance; and which improves the credibility. <P>SOLUTION: This image forming device has an optical sensor 2150 to detect whether there is a medium 30 or not, an exhaustion degree measurement means for the optical sensor 2150, and a calculation means 2108 to calculate the input voltage to be impressed on the optical sensor 2150 within the range of the predetermined input threshold or less. This image forming device characteristically has a light quantity adjusting means 2108 which has a third light quantity adjusting mode that sets the predetermined input threshold as the third input threshold determined, by a measurement value from the exhaustion degree measurement means to have the calculation means 2108 calculate the input voltage, at the cleaning confirmation time for the optical sensor 2150. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus having an optical sensor for detecting the presence / absence of a medium.

[0002]

2. Description of the Related Art The operation of a conventional copying machine will be described with reference to FIG.

FIG. 16 is an overall schematic view of a general image forming apparatus.

Reference numeral 3 is an illumination lamp, 8 is an optical reduction unit, 9 is a second reflecting mirror, 15 is a paper feeding cassette, 19 is a conveying path,
30 is a medium, 50 is a laser control unit, 51 is a laser,
Reference numeral 98 is a CCD, 99 is a first reflection mirror, 100 is a roller, 101 is a photoconductor, 102 is a conveyor belt, 103 is a fixing roller, 104 is a pressure roller, 105 is a transfer unit, and 10 is a transfer unit.
6 is a separation unit, 111 is a paper discharge roller, 112 is a paper discharge roller, 113 is a registration roller, 114a and 114b are conveyance rollers, 121 is a sensor, 122 is a flapper, and 123.
Is a reversing roller, 124 is a reversing position, 125 is a double-sided conveyance path, 126, 127, 128, 129, 130, 131.
Is a sensor, 200 is a roller, 201 is a lever, and 300 is a pickup roller.

Reference numeral 1000 denotes a copying machine (image forming apparatus) main body.

Reference numeral 1001 denotes an automatic document feeder that conveys a document to an exposure position, and reference numeral 1002 denotes a document table glass as document placing means.

The medium 30 is loaded in the paper feed cassette 15.

The medium 30 is usually paper, but there are some which can use so-called OHP film for overhead projector depending on the device.

The pickup roller 300 sends out the loaded medium 30.

The medium 30 is separated into one sheet by a separation sheet feeding roller composed of rollers 100 and 200, and is sent to the conveying path 19.

Then, the transfer rollers 114a and 114b transfer the transfer rollers 114a and 114b to the registration rollers 113, and the
The registration roller 113 operates when other conditions are satisfied.

The image latently formed on the photoreceptor 101 by the optical system or the like is transferred to the medium 30 by the transfer unit 105, and the medium 30 is transferred.
Are separated by a separating unit 106 so as not to be wound around the photoconductor 101 and are sent to the conveyor belt 102.

After that, the medium 30 is conveyed to the fixing roller 103 and the pressure roller 104 by the conveyor belt 102 and fixed by the fixing roller 103 and the pressure roller 104.

Then, the discharge rollers 111 and 11 are directly used.
It is discharged out of the machine by 2.

In the case of performing the double-sided operation, the flapper 122 does not discharge it out of the machine but sends it to the lower double-sided conveyance unit.

When the medium 30 is sent to the lower double-sided conveyance unit, the reversing roller 123 rotates and sends the medium 30 in the A direction.

When the reversing position 124 is reached, the reversing roller 123 rotates in the reverse direction and conveys the medium 30 in the B direction.

Then, the medium 30 is conveyed to the registration rollers 113 through the double-sided conveying path 125.

In this way, the sensors 121, 126, 127, 128, 129, 130, 1 are provided while the medium 30 is passing through the transport path 19, the double-sided transport path 125 and the like.
The reference numeral 31 always detects the current position of the medium 30 to judge whether or not the medium 30 is conveyed normally, and at the same time, the registration roller 113 and flapper 12
2 is controlled.

Conventionally, various sensors have been considered for detecting the position of the medium.

A conventional example of a typical detection sensor will be described below.

A mechanical sensing lever type sensor is shown in FIG.
Shown in.

Reference numeral 201 is a lever, and 202 is a photocoupler.

The lever 201 is arranged so as to block the paper path, and the lever 20 is provided at the tip of the medium 30 passing through the paper path.
When a part of 1 is pressed, the lever 201 rotates to the right, and a signal is emitted by blocking the light flux of the photocoupler 202 arranged near the lever 201 (the signal generating portion is not shown). .

Next, the optical sensor will be described with reference to FIGS.

Reference numeral 205 is a reflection sheet, 212 is irradiation light, and 2
150 is an optical sensor, 2154 is a light emitting element, 2155
Is a light receiving element.

The optical sensor 2150 includes a light emitting element 215.
4 and a light receiving element 2155.

The optical sensor 2150 is roughly as shown in FIG.
The reflective type shown in FIG. 8 and the transmissive type shown in FIG.

In the case of the reflection type, the reflection sheet 2 is provided on the conveying path.
When No. 05 is pasted and the medium 30 is not present, FIG.
As shown in, the reflection sheet 205 reflects the irradiation light 212 of the light emitting element 2154, and the light receiving element 2155 receives the light.

When the medium 30 is present, the medium 30
The presence or absence of the medium 30 is detected by blocking the irradiation light 212.

In this case, however, the medium 30 itself has a drawback that it promotes reflection and causes erroneous detection, as shown in FIG. 18 (B).

For this reason, the accuracy of the medium carrying position is required so that the passing position of the medium 30 does not vary.

Further, the diffused light of the light emitting element 2154 is transmitted to the medium 3
Since there is a possibility that erroneous detection may occur by reflecting the light to 0 and receiving the light, it may be necessary to prevent erroneous detection by a condenser lens or the like in some cases.

Next, in the case of the transmissive type shown in FIG. 19, the light emitting element 2154 and the light receiving element 2155 are arranged so as to face each other with the medium conveying path in between, and the medium 30 crosses the irradiation light 212 of the light emitting element 2154. The presence or absence of the medium 30 is detected.

Although it is possible to prevent the medium 30 itself from promoting reflection, it is required that the relative positions of the light emitting side and the light receiving side be accurate.

In order to make up for each of these drawbacks, as shown in FIG. 20, the light-emitting element and the light-receiving element are refracted by a reflecting plate such as a mirror or a prism to refract the optical axis so that the light-emitting element and the irradiation optical axis of the light-emitting element are changed. , There is a system configured such that the incident optical axis to the light receiving element is parallel.

In FIG. 20, 2152 is a substrate, 2153 is a sealed case, 2200 is a lower transport guide, 2201 is an upper transport guide, 2202 is a mirror, 2203 and 2204 are reflective surfaces.

In this case, the light emitting / receiving elements 2154, 21
Even when the deviation of 55 occurs, the incident light and the reflected light are always parallel, which can widen the allowable range of accuracy and reduce the influence of medium reflection.

As shown in FIG. 20A, the light emitting element 21
54 and the light receiving element 2155 are mounted on the same substrate 2152, and the irradiation light 212 is refracted twice on the prism or the mirror 2202 at an incident angle of 45 degrees to receive the light receiving element 2155.
Return to.

As shown in FIG. 20B, when the medium 30 crosses, the irradiation light 212 is blocked and the presence or absence of the medium 30 is detected.

In the optical sensor system, the light emitting element 2154
The higher the current, the higher the brightness becomes, and a large dynamic range can be obtained depending on the presence or absence of the medium 30, so that the reliability of the detection accuracy is improved.

However, increasing the current value causes a reduction in life.

The mechanical type can be said to be an optical type in that the photocoupler 202 is used, but by providing light emitting / receiving elements 2154 and 2155 within a short distance and shielding by a black member which is not affected by reflection. Even small amounts of light can be detected reliably.

On the other hand, in the optical sensor system, the shielding medium 30 itself may have a high transmittance or a high reflectance, so that it is required to secure a reliably discriminating light amount.

Therefore, when the amount of light is set low, the life is advantageous, but the dynamic range is narrowed, so that the influence of the medium and the influence of dirt become large, and there is a risk of false detection. There is.

Therefore, in the optical sensor system, adjustment must be performed at the initial stage.

Further, even if the initial adjustment is performed, the light emitting portion or the light receiving portion may be contaminated by the paper dust or the like at the time of passing the paper. Therefore, the interval according to the speed of the image forming apparatus and the light quantity reduction degree according to the specification / application is set. It is necessary to adjust the setting and to increase the amount of light little by little to keep the dynamic range constant.

By carrying out this sequence, it is possible to achieve both the securing of the dynamic range and the long-term maintenance-free maintenance of the optical sensor until just before the unadjustable state is reached.

A conventional adjustment method will be described with reference to FIG.

FIG. 21A is a diagram for explaining the factory adjustment mode that is performed during production in a factory.

In FIG. 21B, the power is turned off / off for each job.
It is explanatory drawing of the user adjustment mode performed at the time of ON.

FIG. 21C is an explanatory diagram when the user adjustment mode is frequently performed for each job or the like.

Vin is an input voltage to the light emitting element 2154 of the sensor, and increasing the input voltage increases the light quantity.

Vout is the light receiving element 2155 of the sensor.
However, the amount of light when the irradiation light 212 is received is converted into a voltage.

Vi1 and Vi2 are predetermined input voltages, Vin
MAX is the maximum value of the input voltage which is the upper limit of the input voltage with a margin taken from the maximum rating.

Vs is a threshold voltage, and Vout is V
If it is s or more, the irradiation light 212 is received as it is, so there is no medium, and if Vs or less, it is judged that there is a medium because the irradiation light is blocked.

Vh is an output voltage that is determined to have no problem in determining the medium in consideration of a reduction in the amount of light, and is set in advance according to the characteristics of the image forming apparatus.

VM is the maximum value of Vout.

A1, A2, A3, B1, B2, B3, B
4, C1, C2, D, E, and F are points indicating the performance of the element.

When a predetermined input voltage Vi1 is applied, the light receiving element 2155 outputs it via the voltage conversion circuit.

If the value at this time is equal to or more than Vh set in advance, the adjustment is completed.

21A shows a predetermined input voltage V1.
When i1 is input, since it is already Vh or more, it is determined that adjustment is unnecessary and the adjustment is finished.

In the case of B1 in FIG. 21 (A), that is, when Vh is not more than Vh when the predetermined input voltage Vi1 is input, Vin is increased from Vi1 until it becomes higher than Vh, and becomes more than Vh. If so, the Vin value (V
i2) is set as the control voltage, and the adjustment is completed.

That is, as shown in FIG.
When the characteristic at i1 is at the point of B1, it is Vh or less, so the input voltage is raised, and when it reaches Vi2, it becomes B2 and exceeds Vh, so the initial setting is to operate at the point of B2. Done.

In FIG. 21 (A), when the characteristic at the time of inputting Vi1 is C1, V is set so that a voltage higher than Vh can be obtained.
Even if adjustment is made to increase in from Vi1, it will reach VinMAX, which is the upper limit on the input side, and will not exceed Vh.

In this case, it is treated as a defective product.

Next, the user adjustment mode performed for each job or when the power is turned off / on will be described with reference to FIG.

When the user actually starts the use, even if the voltage of Vi1 which is the initial setting value is applied, the amount of light becomes lower than the initial amount of light due to dirt such as paper dust and toner.
As shown in (B), the output from A1 is attenuated to A2, and V
The level will be below h.

When the voltage further decreases and becomes equal to or lower than the threshold voltage Vs, the presence / absence of the medium 30 cannot be discriminated and the medium cannot operate.

In order to prevent this, adjustments must be made regularly.

To this end, when the output of A2 is output as described above, Vin is increased from Vi1 as in the initial adjustment, and when it becomes Vh or more, the Vin value at that time is changed as the control voltage. , You just have to adjust.

For example, A3 shown in FIG. 21B is the operation point after adjustment.

In the case of B3 in FIG. 21B,
Even if adjustment is made to increase Vin from Vi2, the input reaches the upper limit VinMAX, and the output is V
Never exceed h.

This is B4 in FIG.

In this case, since the dirt is already badly attached and the life of the element is approaching, the control becomes impossible when Vs is lowered.

If the adjustment is performed frequently for each job or the like, as shown in FIG. 21 (C), it becomes close to a straight line that always maintains Vh, and even if Vin increases to points D and E, If the light intensity returns due to cleaning due to service maintenance, etc.
The Vin value returns to near one point.

Then, the operation that Vin increases due to dirt is repeated.

Eventually, the Vin value returned by cleaning due to service maintenance due to element deterioration or the like gradually increases to VinMA.
It becomes closer to X and the life of the element is completed.

[0079]

However, even if the above-mentioned adjustment is performed, the light emitting element / light receiving element has large variations in performance. The variation greatly affects the maintenance interval and the life time, which is a problem.

The details will be described below.

Although the maximum rating of the element itself has been determined, the upper limit of the input voltage in control is set to the maximum rating in consideration of the temperature rise in actual use and environmental factors, as described in FIG. It is decided as VinMAX when the margin is taken from.

Therefore, the larger the distance from point A1 to point F in FIG. 21C, the wider the control range and the long-term maintenance-free operation.

That is, when a considerably high input voltage is set as the initial value in the initial adjustment stage due to variations in performance or the like, for example, when point E in FIG. 21C becomes the initial value, The difference from VinMAX is reduced and the light amount adjustment range is narrowed, which greatly affects the maintenance interval and life time.

In such a case, even a slight stain or a slight deterioration of the element due to a change with time causes adjustment failure or erroneous detection, and maintenance is required immediately.

As a means for solving this problem, the lower limit of the light quantity with respect to a predetermined voltage can be defined to select the elements.

By selecting the elements, the elements having the light amount less than the predetermined value cannot be used, and the yield is deteriorated and the cost is increased. However, as shown in FIG. 21C, if the initial value Vin is low. The lower the value, the wider the light amount adjustment range.

Although it is possible to employ a high-brightness type / high-light-amount type element, there are drawbacks in that it is too large to save space and leads to an increase in cost.

In addition to the above, when the amount of light is reduced due to a mounting adjustment error or the like, as shown in FIG.
As shown in (A), (B), and (C), since it is possible to increase the current value to increase the amount of light, a mounting adjustment error is recovered by the adjustment of the input voltage, and as a result, VinMAX There is a problem that the difference becomes small, the control range is narrowed, and a slight stain due to a change with time causes an erroneous detection.

For example, when there are two single elements having the same characteristics, it is determined that the amount of light is insufficient due to manufacturing errors such as one side being tilted and the other side being dirty, or the reflecting surface being dirty. , The element sets the initial value of the input voltage on the actual machine to a high value by the adjusting mechanism, and becomes, for example, A1 and B2 in FIG. 21 (A), and there is a large difference in the maintenance interval and the life time. Will be.

In particular, since the adjustment mechanism recovers a manufacturing error, there are few problems during factory adjustment, and many maintenance requests and problems occur during use by the user, resulting in a situation of significantly impairing reliability. .

On the other hand, it is conceivable that cleaning by a service person will be carried out in a short cycle at the expense of, for example, a long-term maintenance-free problem, but there remains a problem.

Description will be made with reference to FIG.

O, P, Q, R, P ', Q', and R'are points indicating the performance of the device.

VinTh0 and VinTh1 are input thresholds,
ΔTh is the difference between the input thresholds.

What was point O at the initial stage of factory adjustment deteriorates to point P as the user uses it.

Since Vout is below the medium detection threshold Vh, the medium cannot be detected and cleaning is performed by a service person.

Even if all the dirt such as dust adherence is removed by cleaning, the element itself deteriorates with time, so that the light quantity can be restored only up to point Q.

That is, when a similar output VM is tried to be obtained, the deterioration from the point O to the point P'and even if the stain is removed Q '
It will only recover to the point.

At this time, if the input threshold value is set to VinTh0 (small input), the target output value VM cannot be obtained, so control becomes impossible and the product is treated as a defective product.

As a preventive measure, the input threshold value can be set to a higher value (closer to VinMAX) to VinTh1 in advance. In this case, however, a manufacturing error or an installation error can be recovered when the initial value is set as described above. As a result, the dynamic range is narrowed by ΔTh, which is disadvantageous in terms of life.

If the input threshold value is used only at the time of factory adjustment and not at the time of use by the user, when a trouble (such as insufficient cleaning) occurs at the time of cleaning, recovery is caused by adjusting the input voltage. After all it becomes disadvantageous in terms of life.

The present invention has been made in view of the above problems, and an object thereof is to appropriately set the threshold value of the input voltage during the adjustment in the automatic adjustment of the light amount of the optical sensor. By doing so, a decrease in light amount due to deterioration of the element,
An image forming apparatus capable of improving reliability by determining a decrease in light amount due to mounting error, dirt, etc., and according to the determination, a maintenance interval is long and processing is performed so as to be advantageous in terms of life of the element. To provide.

[0103]

Therefore, in the present invention, the above object is achieved by providing an image forming apparatus shown in any one of the following items (1) to (9). Is.

(1) An optical sensor for detecting the presence or absence of a medium, a consumption degree measuring means for the optical sensor, and a calculating means for calculating an input voltage applied to the optical sensor within a predetermined input threshold or less. In an image forming apparatus having
At the time of confirming the cleaning of the optical sensor, the predetermined input threshold value is set to the third input threshold value determined by the measurement value from the wear level measuring means, and the calculating means calculates the input voltage. An image forming apparatus comprising a light amount adjusting unit having a mode.

(2) The light quantity adjusting means further has a first light quantity adjusting mode, and the first light quantity adjusting mode is
In the mode (1), the mode is such that the predetermined input threshold value is set to the first input threshold value and the calculating unit calculates the input voltage at the time of initial installation / replacement of the optical sensor component. Image forming apparatus.

(3) The light quantity adjusting means further has a second light quantity adjusting mode, and the second light quantity adjusting mode is
The image forming apparatus according to item (1) or (2) above, wherein the predetermined input threshold value is set to a second input threshold value when the user uses the mode, and the calculating unit calculates the input voltage. .

(4) Further, if a display unit is provided and the calculation means cannot calculate an input value within the range of the respective input threshold values or less in each light quantity adjustment mode, a warning display is displayed on the display unit. The image forming apparatus according to any one of (1) to (3) above.

(5) The image forming apparatus according to item (4), wherein the warning display is different depending on each light amount adjustment mode.

(6) The image forming apparatus according to item (1), wherein the consumption measuring means of the optical sensor is a detection counter of the optical sensor.

(7) The image forming apparatus according to item (1), wherein the consumption measuring means of the optical sensor is an output number counter.

(8) When replacing the optical sensor component, the first input threshold value and the third input threshold value are set to the same input threshold value by initializing the measurement value from the wear level measuring means to zero. The image forming apparatus according to item (2) above.

(9) Furthermore, when the calculating means cannot calculate an input value within the range of the respective input threshold values, it has a network connecting means and a host computer connected to the network connecting means. The image forming apparatus according to any one of items (1) to (4), wherein a warning is sent to the host computer.

[0113]

Embodiments of the present invention will be described in detail below with reference to the drawings.

Elements common to the drawings are given the same reference numerals.

Example 1 FIGS. 1 to 11 and 13
Example 1 will be described with reference to FIG.

FIG. 1 is a block diagram of a light emitting and light receiving element of an optical sensor used in the present invention. (A) Side view (B) Perspective view (C) Internal configuration diagram, FIG.
Is a diagram of a drive circuit of an optical sensor used in the present invention, FIG. 3 is a diagram showing an input / output characteristic curve at the time of adjustment of the optical sensor used in the present invention, (A) a diagram reaching VM (B) FIG. 4 is a diagram showing a method in which the adjustment mode is selected from the display unit, which is used in the present invention.
(B) Diagram of designation of sensor location (C) Diagram of designation of adjustment mode, FIG. 5 is a flowchart of adjustment mode 1 used in the first embodiment of the present invention, and FIG. 6 is The figure which shows the input / output characteristic curve at the time of adjustment of the medium detection means used for the Example of this invention, FIG. 7 is the flowchart of the 2nd light amount adjustment mode used for Example 1 of this invention, FIG. FIG. 9 is an overall schematic configuration diagram of a network means used in an embodiment of the present invention, FIG. 9 is a flowchart of a third light amount adjustment mode used in the first embodiment of the present invention, and FIG. 10 is a third light amount adjustment mode used in the present invention. Of the input threshold value in the light amount adjustment mode and the determination contents at that time in the input / output range. FIG. 11 shows a characteristic curve of the detection count CountX-input threshold value ViTH used in the first embodiment of the present invention. It is the figure shown.

FIG. 13A is a flow chart for determining the input threshold value for each mode used in the first embodiment of the present invention.

Reference numerals 2101, 2102 denote operational amplifiers, 210
5 comparator, 2106 is a D / A converter, 210
7 is an A / D converter, 2108 is a microcomputer which is a calculating means and a light amount adjusting means, 2151 is a connector, 28
00 is an operation unit (display unit) such as an LCD formed on the surface of the image forming apparatus, 2900 is an optical medium detection unit,
Q1 is a transistor.

Vi1 to Vi10 are predetermined input voltages, Vo
1 to Vo10 are obtained by converting the amount of light received by the light receiving element 2155 when applying Vi1 to Vi10 to the light emitting element 2154, respectively, into a voltage.

A ', B', C ', D', and E'are points showing the performance of the device, and Vic and Vie are predetermined input voltages.

2411-A, 2411-B, 2411-
C, 2411-D, 2411-E, 2411-F are image forming apparatuses, 2412 is a host computer, 2413 is a network server, and 2414 is a network connection means such as a LAN.

As shown in FIG. 1, the optical sensor 2150
The sealed case 2153 is provided in the
As shown in FIG. 20, a prism or mirror 2202 is provided so as to face 53.

The hermetically sealed case 2153 is formed by a slit that allows light to pass through a synthetic resin or the like that blocks light.

As shown in FIG. 1C, a light emitting element 2154 and a light receiving element 2155 are provided in the sealed case 2153, and the sealed case 2153 itself has a cutout portion, although not particularly specified, to a predetermined position. When inserted, the projection is submerged in the lower part of the substrate 2152, lightly locked and mounted.

On the board 2152, a connector 2151 made of synthetic resin and a part of the circuit shown in FIG. 2 are mounted.

Details of the medium detection operation will be described below with reference to FIG.

First, a predetermined voltage signal is sent from the microcomputer 2108 to the D / A converter 2106.

The D / A converter 2106 is the microcomputer 2
The digital signal of 108 is converted into a voltage.

This voltage allows the operational amplifier 2101 to LE
It is converted into a constant current output for driving D2154, turns on the transistor Q1, and turns on the LED 2154 with a predetermined current.

The structures of the light emitting element 2154, the light receiving element 2155, and the mirror 2202 are the same as those in FIG. 20 shown in the conventional example, and the irradiation light 212 is transmitted through the mirror 2202 to the light receiving element 2.
Return to 155.

The light receiving element 2155 is a phototransistor, and when light of a predetermined wavelength is received, a current flows, and
A voltage is generated across 55.

This voltage is amplified by the operational amplifier 2102 to have a predetermined range width.

During paper passage, the irradiation light 212 is blocked and no current flows through the light receiving element 2155, so the output of the operational amplifier 2102 is 0V.

When there is no paper, the light receiving element 21
55 receives the irradiation light 212 of the LED 2154 and generates an output voltage proportional to the amount of received light.

In the comparator 2105, the output of the operational amplifier 2102 is set to a binary value of H / L at a predetermined voltage set by R10 / R11, and the microcomputer 210
At 8, the presence or absence of paper is determined.

Further, the output of the operational amplifier 2102 is divided into two systems and the like and is also sent to the A / D converter 2107.

As a result, at the time of adjustment, the D / A converter 2
The output of the operational amplifier 2102 when a voltage signal is output to 106 is monitored, and D is set so that the comparator 2105 can obtain the optimum output of the operational amplifier 2102 for determination.
The output value to the / A converter 2106 is determined to obtain an appropriate amount of light emission.

For example, when there is no paper, the irradiation light 212
Is sent to the light receiving element 2155 via the mirror 2202, generates a predetermined voltage equal to or higher than the slice level, is output to the microcomputer 2108 as H level by the comparator 2105, and determines that there is no paper.

If there is paper, the irradiation light 212
Is blocked by the medium 30, so that the irradiation light 212 to the light receiving element 2155 is blocked, and the comparator 21
At 05, the L level is output to the microcomputer 2108 and it is determined that the medium 30 is present.

Although the present embodiment has the D / A converter 2106 and the A / D converter 2107,
It goes without saying that the built-in type microcomputer 2108 may be used.

Further, in this embodiment, the comparator 210
Although it is binarized using 5 to judge the presence or absence of the medium,
You may judge by the output of the A / D converter 2107.

Next, the configuration near the optical sensor will be further described with reference to FIG.

FIG. 20 shows the optical sensor described in the conventional example, in which the sensor of FIG. 1 is attached to the image forming apparatus.

The hermetically sealed case 2153 is used for the lower transport guide 2
It is attached to the position that is close to or as close to 200 as possible.

A prism or mirror 2202 is attached to the upper conveyance guide 2201.

The reflecting surface 2203 faces the light emitting element 2154 in the sealed case 2153, and the reflecting surface 2204 faces the light receiving element 2155.

The reflecting surface 2203 reflects the irradiation light 212 emitted from the light emitting element 2154 in the sealed case 2153, inside the prism or the mirror 2202, and the reflecting surface 223.
Reference numeral 04 again reflects the light reflected by the reflecting surface 2203 (reflected light) and sends the reflected light to the light receiving element 2155 in the sealed case 2153.

The irradiation light and the reflected light extend in the direction intersecting the surface of the medium 30.

Further, the both reflecting surfaces 2203, 2204 have a structure inclined at a predetermined angle in order to reflect the irradiation light 212 in a predetermined direction.

The light emitting element 2154 is composed of a photodiode.

Although not shown in the figure, the sealed case 2
By making the light emission transmitting portion of 153 a convex lens shape,
The light emitted from the light emitting element 2154 is refracted and condensed.

In this case, the light quantity is effective because it can enter the light receiving element 2155 without being attenuated.

Next, Vin- in FIG. 3 (A) and FIG. 3 (B)
The Vout characteristic curve will be described.

Vin is an input voltage to the light emitting element of the sensor, and Vout is a value obtained by converting the light quantity when the light receiving element of the sensor receives the irradiation light into a voltage.

When Vi1 is applied to the light emitting element 2154,
The light receiving element 2155 outputs Vo1 via the voltage conversion circuit.

When Vi2 having a relation of Vi2> Vi1 is input, Vo2 is output.

Similarly, when a voltage is applied in the relationship of Vi (n + 1)> Vin, the increase of the input voltage directly increases the light amount and the output also increases, but the microcomputer 2108 and the A / D converter 2107 are also used. In order to protect the input of the control unit, a diode of D2 is used to prevent the voltage from exceeding a certain level by a diode clamp or the like.

Next, the designation of the adjustment mode during the adjustment operation will be described.

FIG. 13A shows how to specify the adjustment mode.

First, in S3001 of FIG. 13A, it is selected whether or not the component mounting / replacement mode is selected.

When the component mounting / replacement mode is selected,
In S3002, the first input threshold value ViTh0 is set to Vi10 which is the input threshold value of the first light amount adjustment mode described later.

ViTh0 is an MI whose machine specifications are acceptable.
Since it is N, the setting is performed according to the specifications.

Then, the first light amount adjustment mode is designated.

In the user adjustment mode, FIG.
When the component attachment / replacement mode is not designated in S3001 of (A) and the cleaning confirmation mode is not designated in S3003, the second light amount adjustment mode is designated.

In the cleaning confirmation mode in which the service person or the like makes adjustments after cleaning, S3001 in FIG.
Do not specify the component installation / replacement mode in step S30.
In 03, the cleaning confirmation mode is designated, and in S3004, a third input threshold value ViThX to be described later is calculated.

Then, the third light amount adjustment mode is designated.

Note that ViThX = F (CountX) can be written, and F (CountX) is calculated from a variable CountX which is the value of the consumption level measuring means (detection number counter or output number counter) (not shown) of the optical sensor. This is the function to be determined.

Next, FIG. 4 shows a state of the operation for entering the adjusting operation.

First, by inputting a secret code or the like on the operation unit 2800, the mode is shifted to the factory mode or the service mode.

At the time of initial installation, it is designated from the factory mode, and when the optical sensor is replaced, the light quantity adjustment item is selected (see FIG.
(A)) Then, the location of the sensor to be adjusted (replaced) is designated (FIG. 4B).

Finally, the adjustment mode is designated (see FIG. 4).
(C)).

By this designation, S30 of FIG.
01, the determination of S3003 is made.

The user adjustment mode is automatically started when the power is turned on.

Note that FIGS. 4B and 4C show the double-sided pass 1
It is a figure when the optical sensor of is replaced.

Next, the operation of the first light amount adjustment mode is shown in FIG.
Shown in.

First, in S2001 of FIG. 5, a light amount adjustment start command is input.

In this case, the input from the operation unit 2800 may be used, or the constitution may be such that it automatically starts when the power is turned on.

Next, after resetting the counter N to 1 in S2002, in S2003, from the microcomputer 2108,
A predetermined digital signal corresponding to Vi1 is output, and the LED 2154 is caused to emit light according to the detailed description of FIG.

Then, the light amount received by the phototransistor 2155 in S2004 is converted to the A / D converter 210
The value is converted into a voltage value at 7 and read by the microcomputer 2108.

The value of Vi1 is a value defined by the light amount variation MAX.

Therefore, in S2005, Vi1
If it has already reached VM, since it is too bright, there is a risk of erroneous detection due to medium reflection, so the flow proceeds to S2012 and is determined to be NG.

In this case, a message such as "Please replace parts" is displayed on the display unit 2800 or the like.

On the other hand, if the VM is not reached at Vi1, the microcomputer 2108 stores the S in the storage unit (not shown).
In 2006, input voltage values ViN and VoN (in this case N
= 1) is stored.

The storage unit does not need to be provided in the microcomputer 2108, and may be an accessible external element.

Then, in S2007, the counter N is incremented by 1, and in S2008, it is determined whether the preset output / input has been performed 10 times.

In this embodiment, V as shown in FIG.
Although it is set to 10 times up to i10, the number of times is obtained by previously dividing the signal output from the microcomputer 2108 within a certain range, and can be freely set to 8 divisions or 16 divisions.

However, the higher the number of times, the higher the accuracy but the longer the time.

If it has not reached 10 times in S2008, the flow returns to S2003 to output a predetermined digital signal from the microcomputer 2108.

In this case, the digital signal is output so as to become Vi2 which is a predetermined amount higher than the previous input Vi1.

A voltage is applied in the relationship of Vi (N + 1)> ViN.

In this embodiment, the MIN is obtained by the above-mentioned 10 divisions.
Input from Vi1 to MAX Vi10 sequentially.

When the routine from S2003 to S2008 is completed 10 times, the process proceeds to S2009, and it is determined whether or not the preset voltage value is reached.

The set voltage value referred to here is Vout.
That is, the irradiation light 212 capable of sufficiently recognizing the presence or absence of the medium is received.

If the preset voltage value has been reached, it is judged to be OK, and when the change amount becomes 0 between Vo1 and Vo10 in S2010, that is, the Vin value at which Vo (n + 1) -Von = 0. Then, the smallest Vin value is set as the control value, and the adjustment ends in S2011.

In FIG. 3A, the saturation voltage VM is reached when Vi8 is input, and VM is always obtained even when a voltage of Vi8 or higher is applied, and since the variation amount is 0, Vi8 is applied. It will function as a sensor enough.

Therefore, Vi8 is set as the controlled input voltage by factory adjustment.

On the other hand, if VM has not been reached in S2009, that is, if the preset voltage value VM has not been reached, as shown in FIG. 3B, the flow proceeds to S2014, and it is determined to be NG.

In S2014, NG display such as "please check the parts and mounting" is displayed on the display unit 2800 or the like.

As soon as the adjustment is completed, the judgment display is made sequentially or collectively.

When confirmation or treatment is performed in S2015, the adjustment from S2002 is started again.

If YES in S2005,
Since the light amount is over, it can be limited to defective parts (S201
2) When S2009 becomes NG, it can be understood that there is a possibility of stain adhesion / attachment error / part defect due to insufficient light quantity on the light emitting side / light receiving side.

After both treatments (S2013, S2015), the adjustment is performed again, and if OK, the display is switched to OK.

The range from Vi1 to Vi10 is set according to the characteristics of the mounting location.

For example, if the area is easily soiled, Vi10
By setting a low value, the adjustment range up to the output MAX can be widened, and the maintenance interval can be lengthened.

Next, the second light amount adjustment mode will be described.

In the user adjustment mode, S in FIG.
3001 does not specify the component installation / replacement mode,
When the light amount adjustment is performed (such as automatically when the power is turned on) in a state where the cleaning confirmation mode is not designated in S3003, the process proceeds to the second light amount adjustment mode.

The second light amount adjustment mode is set to Vin- in FIG.
This will be described with reference to the Vout characteristic curve and the flowchart of FIG.

The graph of FIG. 6 is mainly the power source OF of the user.
It is a figure which shows the power supply ON adjustment mode which seems to be desirable at the time of F / ON or between jobs.

When the user actually starts using the image forming apparatus, the amount of light becomes lower than the initial light amount even if the voltage of Vi8 which is the initial setting value is applied due to dirt such as paper dust and toner, as shown in FIG. Thus, for example, from A'to B ', that is, the output voltage is reduced from the level of VM to Vo5.

If it continues to be used as it is and is further lowered to become equal to or lower than the threshold voltage Vs, the presence or absence of the medium 30 cannot be discriminated, and the medium 30 does not operate.

[0211] In order to prevent this, adjustment is performed regularly.

First, at S2300 in FIG. 7, the power is turned on.
Then, the light amount adjustment is started in S2301.

Then, in S2302, the light emitting element 2
ViN is output to 154, and VoN obtained by converting the amount of light received by the light receiving element 2155 is read.

For example, in FIG. 6, it is assumed that the output is reduced from the previously set A'to B'due to stains such as paper dust and toner, and the adjustment is performed at the B'point.

In this case, ViN which is ViN is output, and Vo5 which is output VoN is read in S2303.

Since it suffices to increase the input voltage ViN by the ratio of the output VoN when the output voltage MAX is reduced by VM due to contamination, it may be adjusted as VM ÷ VoN × ViN.

By applying this to the point B'in FIG. 6, it becomes VM ÷ Vo5 × Vi8 = Vic.

Next, in S2304, VinMAX> VM
÷ Determine whether VoN × ViN.

Applying to the point B'in FIG.
Since the relationship of nMAX> Vin (Vic) is established, the process proceeds to S2305, the adjusted input voltage is set to Vic, and the output VM is obtained.

Then, the adjustment ends in S2306.

Setting the input voltage value to Vic means setting it to point C'in FIG. At this time, no special display is made.

However, the output VM may not be obtained by this adjustment.

For example, in the case of the adjustment in the case where after the point C'is set in FIG. 6 and the point D is further changed due to dirt such as paper dust or toner, when applying the above-mentioned calculation formula, it becomes VM ÷ Vo5 Since × Vic = Vie, Vin (Vie)> Vin in S2304
It becomes MAX, and the microcomputer 2108 cannot output the Vie value.

Therefore, the processing advances to S2307, and VinM
Set AX as the adjusted input voltage.

In this case, if the use is continued, V
Since "out" becomes equal to or less than the threshold value Vs and it becomes impossible to determine the presence or absence of the medium 30, the "clean" message is displayed or notified in S2308.

In the second light amount adjustment mode, the input threshold value V
Input is made within the range of inMAX or less.

Since some dirt due to paper dust or the like can be recovered by automatic adjustment, long-term no-maintenance can be realized without making repeated cleaning requests.

Further, in the image forming apparatus having the network means, the life parameter can be notified by remote control.

[0229] Fig. 8 is a diagram showing the configuration connected on the network.

The adjustment mode is the same as that in the flow chart of FIG. 7, and steps S2301 to S2307 are performed in the same flow.

At S2404, Vin (Vie)> V
If it is determined to be inMAX, since the microcomputer cannot output the Vie value, the input voltage value is set to Vin in S2307.
Set to MAX, and in step S2309, the host computer 2412 via the network connection unit 2414.
Will be notified to request maintenance.

As a result, the administrator and the service person are notified and maintenance is performed without the user being particularly concerned about the state, so that an unexpected situation can be avoided.

Next, the third light amount adjustment mode will be described.

In the cleaning confirmation mode, S3 in FIG.
Do not specify the component installation / replacement mode in 001,
A cleaning confirmation mode is designated in S3003, and a third input threshold value ViThX, which will be described later, is calculated in S3004.

Then, in S3005 of FIG.
ViThX is set to Vi10 and the mode shifts to the third light amount adjustment mode.

The third input threshold value ViThX is ViThX.
= F (CountX), and F (CountX)
Is the value Co of the wear level measuring means (detection number counter or output number counter) (not shown) of the optical sensor.
This is a function determined from untX.

Then, as shown in FIG.
As the value of X becomes larger (the number of days used), ViT
It is a function that changes toward VinMAX so that h (X-1) <ViThX.

The third light amount adjustment mode will be described with reference to the flowchart of FIG.

This is basically the same as the operation in the first light amount adjustment mode shown in FIG.

What is different is that Vo1 = VM? After reading the voltage value of the A / D converter 2107 in S2504.
That is, the determination of (too bright) is not performed.

This is because defective parts due to element variations are made at the time of mounting.

After S2505, the operation is the same as in the first light amount adjustment mode.

However, the warning display in S2511 when the NG determination is made in S2508 can be specialized as "cleaning is insufficient".

When CountX = X, as shown in FIG. 10, the upper range of the Vin-Vout characteristic straight line connecting the intersection points of the input threshold VinThX and the output VM is the normal determination area, and the lower range is defective. It becomes the judgment area.

By setting the input threshold value from the input threshold value VinTh0 at the time of mounting / replacement of the initial parts to the third input threshold value ViTh1 in consideration of the decrease in the light amount due to the change over time, cleaning is performed without careless recovery. It is possible to prevent problems such as insufficient or improper installation.

Furthermore, since there is a margin for deterioration, it is not necessary to make an impossible restoration request.

The Vin-Vout characteristic curve of FIG. 22 and the number of detection times CountX-input threshold value V of FIG. 11 from the initial installation to the time when the user starts use and performs cleaning due to dirt.
This will be described using iTH.

For example, at the time of factory installation, as shown in FIG. 22, the input threshold value VinTh0 is adjusted to the O point in the first light amount adjustment mode.

Here, elements having large element variations are excluded, and the input threshold value is strict (small), so that mounting failure can be prevented.

Next, the output voltage (output light amount) obtained by the user's use, which is caused by the deterioration of the element and the contamination, decreases to the P point.

Since Vout is equal to or lower than the detectable Vh, the second light amount adjustment is performed and the P'point at which VM is obtained is calculated.

Here, since the input voltage is higher than VinMAX, the cleaning request is displayed or the network connection means 241.
4 to the host computer 2412, and the input value Vin is set to VinMAX.

When used by the user, if it can be detected, a decrease in the light amount due to dirt is recovered to some extent, and no frequent cleaning requests are made, so long-term maintenance is realized (second light amount adjustment mode).

[0254] Eventually, when the dirt becomes severe, a cleaning notification is given, and the cleaning is performed by the service person who received the cleaning notification.
The output light quantity is restored from the point to the Q point.

At the time of confirmation after cleaning, according to the detection count CountX-input threshold value ViTH characteristic curve of FIG.
For example, the count of detections by the optical sensor CountX = 2000
The input threshold value that is the intersection of 0 is ViTh1 (= F (2000
0)) becomes Q'point by the third light amount adjustment mode.

If the number of detections CountX = 50000
In the case of, it becomes ViTh2.

Here, CountMAX is the number of times that the output number of sheets defined by the machine specifications is provided with some margin.

Although the characteristic curve is shown as a proportional straight line in FIG. 11, it goes without saying that it is shown as a quadratic curve or the like depending on the life deterioration characteristic of the sensor.

The Q'point in FIG. 22 is the input VinQ.
If ViTh1, it is determined that the cleaning is sufficient, and the second light amount adjustment mode when the user is using is performed again when the power is turned on or between jobs.

At this time, if the input threshold value is the same as the initial value V
If iTh0, VinQ> ViTh0, so
No matter how much cleaning is done, it is regarded as insufficient cleaning and it becomes out of control.

Even if the cleaning is performed, it is possible to change the R from the P point.
When the amount of light is restored only up to the point, it is adjusted to the R'point, but VinR '> ViTh1 is displayed, so "Inadequate cleaning" is displayed.

At this time, if the input threshold is VinMAX.
In that case, VinR '<VinMAX, and recovery occurs despite insufficient cleaning, resulting in shortened life.

According to the present invention, it is possible to surely prevent a defect.

Example 2 The image forming apparatus of Example 2 is
The light amount adjustment mode after the input threshold value ViTH is calculated is common to the first light amount adjustment mode, the same effect as that of the first embodiment can be obtained, and the processing control can be further simplified. Is.

Since the structure and the circuit are the same as those of the first embodiment, the same structures are designated by the same reference numerals and detailed description thereof will be omitted.

The second embodiment will be described with reference to the flowcharts of FIGS. 12 and 13B and the Vin-Vout characteristic curve of FIG.

FIG. 12 is a flow chart of the light amount adjustment mode used in the second embodiment of the present invention, FIG. 13 (B).
FIG. 14 is a flowchart for determining an input threshold value for each mode used in the second embodiment of the present invention, and FIG. 14 is a diagram showing an input / output curve during adjustment used in the second embodiment of the present invention.

In FIG. 14, H, I, J, and K are points indicating the performance of the element, ViI and ViK are input voltages at the points I and K, and VoH and VoJ are points H and J. Light receiving element 21
55 Pre-converted light quantity received by Vi 55
Is the input voltage before adjustment.

First, in the flowchart of FIG.
Determine iTH.

In S3006, it is selected whether or not the component mounting / replacement mode is set.

When the component mounting / replacement mode is selected,
In S3007, the input threshold is ViTH and the first input threshold V is
iTh0 is set and the mode shifts to the first light amount adjustment mode.

ViTh0 is an MI whose machine specifications are acceptable.
Since it is N, the setting is performed according to the specifications.

If the component attachment / replacement mode is not set in S3006, the input threshold value ViThX in consideration of deterioration with time is calculated in S3008.

Since the method of calculating ViThX has been described in the first embodiment, it will be omitted here.

If it is not in the cleaning confirmation mode in S3009, the second input threshold VinMAX is set to ViTH in S3011, and the process shifts to the first light amount adjustment mode.

If it is in the cleaning confirmation mode in S3009, the third input threshold value ViTh is added to ViTH in S3010.
X is set and the mode shifts to the first light amount adjustment mode.

The calculation of the third input threshold value in S3008 may be performed after the cleaning confirmation mode is recognized in S3009.

Then, in S2701 of FIG. 12, the first
The light intensity adjustment mode of starts.

In the second embodiment, there is one light quantity adjustment mode.

[0280] In step S2702, the optical sensor 2150 is set to ViN.
Is output, and VoN is read in S2703.

For example, if the adjustment is being made at the H point in FIG. 14, ViPre is input and S2703 is entered.
The output VoH is read with.

Since the light quantity is reduced, the input voltage is increased at the reduced ratio.

Since VM ÷ VoN × ViN, this is applied to the H point in FIG. 14, VM ÷ VoH × ViPre = ViI.

At this time, if the input threshold value ViTH is larger than ViI, ViTH> Vin (Vi
Since the relationship I) is established, in S2705,
Set the input voltage value to ViI.

In FIG. 14, it means that the point I has been set. S
The adjustment ends in step 2706.

In the adjustment at the J point, similarly, S270
Input ViPre at 2 and read output VoH at 2703.

Applying to the above formula, VM ÷ VoJ × ViPre = ViK Becomes

At this time, if the input threshold value ViTH is smaller than ViK, Vin (ViK)> Vi in S2704.
It becomes nTH, and the microcomputer 2108 cannot output the ViK value.

Therefore, in S2707, the input voltage value is set to ViTH.

In this case, if the use is continued, the threshold value will eventually be exceeded and the presence / absence of the medium 30 cannot be determined. Therefore, a warning is displayed in S2708.

According to this embodiment, the warning is displayed before the operation is disabled. Therefore, by performing the operation as displayed,
It is possible to avoid inoperability.

As described above, if the light amount adjustment mode after the calculation of the input threshold value ViTH is made common to the first light amount adjustment mode, the same effect as in the first embodiment can be obtained and the processing control can be further improved. It can be simplified.

(Third Embodiment) Next, a third embodiment will be described with reference to the flowchart of FIG.

FIG. 15 is an input threshold value determination flowchart for each light amount adjustment mode used in the third embodiment of the present invention.

The operation of the light amount adjustment mode of the third embodiment is the same as the operation shown in the first embodiment, and will be omitted.

First, if the user adjustment mode is set in S3012, the input threshold value VinMA is added to ViTH in S3013.
X is set and the mode shifts to the second light amount adjustment mode.

If it is not in the user adjustment mode in S3012 or in the parts mounting / exchange mode in S3014, the number of times of detection by the optical sensor or the number of output sheets of the image forming apparatus is set to CountX.

If it is the component mounting / replacement mode, S301
Clear the Count X to zero at 5.

In S3016, the input threshold value ViThX in which ViTH is taken into consideration in consideration of deterioration over time is calculated, and in S3017, ViTh is calculated.
ViThX is set to TH, and the mode shifts to the first light amount adjustment mode (third light amount adjustment mode).

At this time, if CountX = 0, then F
Since (0) = ViTh0, the first input threshold value and the third
The same input threshold can be used as the input threshold and the first light amount adjustment mode and the third light amount adjustment mode can be treated as the same mode.

As described above, according to the third embodiment, the first light amount adjustment mode at the time of initial mounting / replacement of parts and the third light amount adjustment mode at the time of cleaning confirmation can be treated as the same mode, and the process control can be performed. Can be more simplified.

[0302]

As described in detail above, according to the present invention, in the automatic adjustment of the light quantity of the optical sensor, the threshold value of the input voltage is appropriately set at the time of the adjustment, so that the light quantity is reduced due to the deterioration of the element. An image forming apparatus capable of improving reliability by determining a decrease in light amount due to a mounting error, dirt, etc., and according to the determination, processing is performed so that maintenance intervals are long and the life of the element is advantageous. Can be provided.

An optical sensor for detecting the presence / absence of a medium, a consumption degree measuring means for the optical sensor, a driver section for applying an input voltage to the optical sensor to control the light quantity,
A conversion unit that converts the output current of the optical sensor into an output voltage, a comparison unit that compares a predetermined light amount with the light amount of the optical sensor, and the optical sensor in a range that is less than or equal to a predetermined input threshold value according to the comparison unit. An image forming apparatus having a calculating means for calculating an input voltage applied to the optical sensor component, the calculating means is configured to perform the first attaching / replacement of the optical sensor component.
A first light amount adjustment mode in which an input value is calculated within a range less than or equal to the input threshold value; and a second light amount adjustment mode in which the calculation means calculates an input value within a range less than or equal to a second input threshold value when used by the user, At the time of confirming the cleaning of the optical sensor, the calculating means includes a light quantity adjusting means in a third light quantity adjusting mode for calculating an input value within a range equal to or less than a third input threshold value determined by the measurement value from the wear level measuring means. By providing an image forming apparatus characterized by including the following, when a predetermined current value is input and the output voltage does not fall within a predetermined output voltage level range, a desired life of the machine or a maintenance interval is satisfied. It is judged that there is a problem that can not be done (installation error, adhesion of dust, variation, etc.) and a warning is displayed, so it is possible to prevent the life from shortening due to simple installation error or dust adhesion. Come, it is possible to improve the reliability.

Then, the initial installation in which the parts are new,
Or, in the first light quantity adjustment mode during parts replacement, there is no contamination due to aging and there is a large element variation / attachment failure factor, so the input threshold is set to a stricter (smaller) first input threshold. It is possible to prevent problems such as mounting failure by not performing unnecessary recovery.

[0305] When the power is turned on when the user is using or JOB
In the second light amount adjustment mode performed in between, VinMAX
By setting to the second input threshold value, some dirt due to paper dust or the like can be recovered by automatic adjustment, and long-term no maintenance can be realized without making repeated cleaning requests.

In the third light quantity adjustment mode after cleaning by a service person, a value considering the decrease in light quantity due to a change over time is set as the third input threshold value from the input threshold value at the time of mounting / replacement of initial parts. It is possible to prevent problems such as insufficient cleaning or improper installation without carrying out recovery.
Also, since there is a margin for deterioration, it is possible to avoid making an impossible restoration request.

[0307] In addition, when the calculation means cannot calculate the input value in the range of the respective input threshold values or less in each light quantity adjustment mode, the display section displays a warning, and further, By changing the warning display according to the light amount adjustment mode, it is possible to respond more appropriately and promptly.

Further, as the consumption degree measuring means of the optical sensor, the detection number counter of the sensor or the output number counter of the image forming apparatus is used, so that it is not necessary to add new measuring means.

Even if the light amount adjustment mode is not divided into three modes, the first input threshold value and the third input threshold value are set to zero by initializing the measurement value from the wear level measuring means at the time of replacement of the optical sensor parts. It is possible to treat the first light amount adjustment mode at the time of initial installation / replacement of the component and the third light amount adjustment mode at the time of cleaning confirmation as the same mode by using the same input threshold value of 1 as the same input threshold value, and further simplify the control. .

Further, it has a network connection means and a host computer connected to the network connection means,
By notifying the host computer via the network of a warning when the calculating means cannot calculate an input value within the range of the respective input thresholds, E maintenance is realized, and unnecessary visits by service personnel are eliminated. Can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram of a light emitting element and a light receiving element of an optical sensor used in the present invention. FIG. 1A is a side view. FIG. 1B is a perspective view. FIG.

FIG. 2 is a diagram of a drive circuit of an optical sensor used in the present invention.

FIG. 3 is a diagram showing an input / output characteristic curve at the time of adjustment of an optical sensor used in the present invention.
(B) It is a figure which did not reach VM.

FIG. 4 is a diagram of a method of selecting an adjustment mode from a display unit used in the present invention (A) A diagram of selection of a light amount adjustment item
(B) Diagram of designation of sensor location (C) Diagram of designation of adjustment mode.

FIG. 5: Adjustment mode 1 used in Example 1 of the present invention
It is a flowchart of.

FIG. 6 is a diagram showing an input / output characteristic curve at the time of adjustment of the medium detection unit used in the embodiment of the present invention.

FIG. 7 is a flowchart of a second light amount adjustment mode used in the first embodiment of the present invention.

FIG. 8 is an overall schematic configuration diagram of network means used in an embodiment of the present invention.

FIG. 9 is a flowchart of a third light amount adjustment mode used in the first embodiment of the present invention.

FIG. 10 is a diagram showing the change of the input threshold value in the third light amount adjustment mode used in the present invention and the determination content at that time in the input / output range.

FIG. 11: Number of detections C used in Example 1 of the present invention
It is the figure which showed the characteristic curve of outX-input threshold value ViTH.

FIG. 12 is a flowchart of a light amount adjustment mode used in the second embodiment of the present invention.

FIG. 13 is a flowchart for determining an input threshold value for each mode used in the first and second embodiments of the present invention. (A) Flowchart of the first embodiment (B) Flowchart of the second embodiment.

FIG. 14 is a diagram showing an input / output curve during adjustment, which is used in Example 2 of the present invention.

FIG. 15 is an input threshold value determination flowchart for each light amount adjustment mode used in the third embodiment of the present invention.

FIG. 16 is an overall schematic diagram of an image forming apparatus for explaining the present invention and a conventional example.

FIG. 17 is a conventional medium detection unit.

FIG. 18 is a diagram of medium detecting means of the present invention and a conventional example.
FIG. 6A is a diagram showing light reception and FIG. 8B is a diagram showing false detection.

FIG. 19 is a medium detecting means of the present invention and a conventional example.

FIG. 20 is a diagram of medium detecting means of the present invention and a conventional example.
(A) A diagram showing a state without a medium (B) A diagram showing a state of medium detection.

FIG. 21 is a diagram showing an input / output characteristic curve at the time of adjustment in the conventional example. (A) A diagram showing a factory adjustment mode. (B) A diagram showing a user adjustment mode. (C) A diagram showing a case where the user adjustment mode is frequently performed. is there.

FIG. 22 is a diagram showing an input / output characteristic curve at the time of adjustment in the conventional example.

[Explanation of symbols]

2108 Microcomputer 2150 Optical sensor 2153 sealed case 2154 light emitting device 2155 Light receiving element 2202 Prism (mirror)

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Ikuo Takeuchi             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation (72) Inventor Kunio Tsuruno             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation (72) Inventor Kenji Fukushi             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation (72) Inventor Masahiro Kurahashi             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation F term (reference) 2H027 DA01 DA41 DA45 DC03 DE02                       EF01 GA30 GB07 HB01 HB05                       HB06 HB16 ZA07                 2H072 AA09 AA16 AA22                 3F048 AA01 AB01 BA05 BB10 CC01                       DA06 DC12

Claims (9)

[Claims] 1. An optical sensor for detecting the presence or absence of a medium,
In an image forming apparatus having a consumption measuring means for the optical sensor and a calculating means for calculating an input voltage applied to the optical sensor in a range equal to or less than a predetermined input threshold value, when confirming cleaning of the optical sensor, Third, the predetermined input threshold value is determined by a measurement value from the wear level measuring means.
The image forming apparatus is provided with a light amount adjusting unit having a third light amount adjusting mode for causing the calculating unit to calculate the input voltage with the input threshold value of 1. 2. The light quantity adjusting means further has a first light quantity adjusting mode, wherein the first light quantity adjusting mode sets the predetermined input threshold value to a predetermined value when the optical sensor component is initially mounted or replaced. The image forming apparatus according to claim 1, wherein the image forming apparatus is in a mode in which the input voltage is set to 1 and the calculating unit calculates the input voltage. 3. The light quantity adjusting means further has a second light quantity adjusting mode, wherein the second light quantity adjusting mode sets the predetermined input threshold value to a second input threshold value when the user uses the light quantity adjusting mode. The image forming apparatus according to claim 1, wherein the image forming apparatus is in a mode in which the calculating unit calculates the input voltage. 4. A display unit is further provided, and in each of the light amount adjustment modes, when the calculation unit cannot calculate an input value within a range equal to or less than each of the input threshold values, a warning is displayed on the display unit. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. 5. The image forming apparatus according to claim 4, wherein the warning display is different for each light amount adjustment mode. 6. The consumption measuring means of the optical sensor,
The image forming apparatus according to claim 1, wherein the image forming apparatus is a detection frequency counter of the optical sensor. 7. The consumption measuring means of the optical sensor comprises:
The image forming apparatus according to claim 1, wherein the image forming apparatus is an output sheet counter. 8. When replacing the optical sensor component, the first input threshold value and the third input threshold value are set to the same input threshold value by initializing the measurement value from the consumption level measuring means to zero. The image forming apparatus according to claim 2, wherein 9. If the network connection means and a host computer connected to the network connection means are provided, and the calculation means cannot calculate an input value within a range equal to or less than each of the input thresholds, the network is connected through the network. The image forming apparatus according to claim 1, wherein the host computer is notified of a warning.