JPH08137145A - Image forming device and detector - Google Patents

Abstract

PURPOSE: To provide an image forming device which is capable of most adequately controlling image forming conditions in spite of an environmental change and a detector which does not take time in detection of a detecting object and with which the reduction of a size and cost is possible. CONSTITUTION: This device has a detector 29 which has plural light emitting parts 35, 36 of different light emission wavelengths for detecting the detecting object and a light receiving part 37 for receiving the light emission outputs thereof and a control section 34 which takes in the light reception outputs of the light receiving section 37 in accordance with the light emission signals to successively operate plural light emitting parts 35, 36 to emit light, judges the moisture content of the detecting object from the results of the comparison and controls the image forming conditions in accordance with the results of the judgment at the time of starting the image forming operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a copying machine, a facsimile,
The present invention relates to an image forming apparatus such as a printer and a detection apparatus.

[0002]

2. Description of the Related Art Image forming apparatuses include copying machines, facsimiles,
There is a printer. For example, in an electrophotographic copying machine, a photoconductor is rotated to uniformly charge the photoconductor by a charging device, and then an electrostatic latent image is formed by exposing a document image to the photoconductor by exposing means. The image is developed with a developer in a developing unit to form a toner image, which is transferred by a transfer device to a transfer paper from a paper feeding device such as a paper feeding tray. After the transfer paper is separated from the photoconductor, the toner image is fixed by the fixing device and discharged as a copy, and the photoconductor is cleaned by the cleaning device after the transfer to prepare for the next image formation. The image forming portion constitutes an image forming system, and a corona charger, a transfer belt or the like is used as the transfer device.

Such an image forming apparatus is particularly susceptible to humidity fluctuations among environmental fluctuations, and the amount of water (moisture content) of the transfer paper set in the paper feed tray, the developer in the developing section, the transfer belt, etc. ) Is one of the causes of unstable image forming conditions.
It has become one. Therefore, in order to maintain stable image quality in various environments, a sensor that detects temperature and humidity is provided around the image forming system and outside the device, and the value set in advance from the state of the atmosphere detected by this sensor is set. Based on this, each part of the image forming system is controlled. For transfer paper that is easily affected by environmental changes, if the power cord of the device is inserted into an outlet in order to make it less likely to be affected by environmental changes, the transfer paper of 10 to 30 W provided at the bottom of the paper feed tray will be used. The heating device operates to constantly dry (dehumidify) the transfer paper. This heating device is turned off during the image forming operation.

Further, a detection device including a light emitting portion (light source) and a light receiving portion is installed in each portion of the image forming apparatus and used for detecting various kinds of detected objects, or used for detecting detected objects other than the image forming apparatus. It is being done. This detection device is provided with a filter for transmitting light of a different wavelength on either the light emitting portion side or the light receiving portion side and integrally configured as a set of a light emitting portion, a light receiving portion and a filter for each detection wavelength, There is a filter in which the filter is replaceable and the filter is replaced every time a detection object is detected.

[0005]

In the above-mentioned image forming apparatus, a sensor for detecting temperature and humidity is provided around the image forming system and outside the apparatus, and a value set in advance from the state of the atmosphere detected by this sensor is used. Although each part of the image forming system is controlled, the sensor does not correctly detect the temperature and humidity of the target object for temperature and humidity detection, so there was the inconvenience that optimum control of each part of the image forming system could not be performed. . In addition, since the transfer paper in the paper feed tray is dried by the heating device, the heat accumulated in the transfer paper is carried to the photoconductor side by the paper feed conveyance of the transfer paper during image formation, and abnormalities in the photoconductor and the device occur. Electric power is wasted because it causes heating and keeps the heating device constantly operating.

Generally, the transfer paper is fed from the uppermost one of the paper feed trays, but the transfer paper may be replenished in the paper feed tray during the copying operation, and the transfer paper is not necessarily fed from the paper feed tray. The paper is not always fed with the optimum water content. The transfer paper is suitable as a paper for transferring an image when the water content is 4 to 8%. When the water content of the transfer paper is 10% or more, the transfer efficiency of the transfer paper may be lowered and the separation efficiency may be lowered, a paper feed error may be caused, and wrinkles may be generated in the fixing device and toner may not be fixed.

In the above detection device, if the filter is replaceable and the filter is replaced every time the detection object is detected, it takes time to detect the detection object, which is not suitable for downsizing the device. Further, in the case where the light emitting portion, the light receiving portion, and the filter are integrally formed as one set for each detection wavelength, the number of parts increases, the cost becomes high, and it is not suitable for downsizing the device.

The present invention solves the above problems, and an image forming apparatus capable of optimally controlling the image forming conditions even when the environment changes, and cost reduction and downsizing because it does not take time to detect a detection object. An object of the present invention is to provide a measuring device that can be measured.

[0009]

In order to achieve the above object, the invention according to claim 1 is an image forming apparatus for forming an image corresponding to an input image on a recording medium, and is arranged at a predetermined position in the apparatus. A detection device having a plurality of light emitting units having different emission wavelengths for detecting a detection object and sequentially emitting light, and a light receiving unit for receiving a light emission output from the plurality of light emitting units, and the plurality of light emitting units in sequence. The light-receiving output from the light-receiving unit is taken in based on the light-emitting signal for the light-emitting operation, and the water content of the detected object is judged based on the preset value from the comparison result of these light-receiving outputs, and the image forming operation is started. A control unit for controlling preset image forming conditions based on the result of the above determination is provided.

According to a second aspect of the present invention, there are provided a plurality of light emitting portions having different emission wavelengths, and a light receiving portion for receiving light emission output from the plurality of light emitting portions, and the plurality of light emitting portions are spectroscopic of the light receiving portion. A light emitting portion having a peak sensitivity at 1.45 μm on the long wavelength side of the sensitivity and 0.8 on the short wavelength side of the spectral sensitivity of the light receiving portion.
a light emitting section having a peak sensitivity to μm, and the plurality of light emitting sections and the light receiving section are arranged at a predetermined angle,
The outputs of the plurality of light emitting units and the light receiving unit can be set by an external input.

According to a third aspect of the present invention, in an image forming apparatus for forming an image corresponding to an input image on a recording medium, a detection device arranged at a predetermined position in the device to detect a detection object, and the detection device. The storage data of the storage means for storing the data of (1) is updated by the data from the detection device based on an internal preset time, and the storage means is based on the input signal for starting the image forming operation and the subsequent signal. And a control unit for controlling preset image forming conditions based on the internal data.

[0012]

According to the first aspect of the present invention, in the detection device, the plurality of light emitting portions having different emission wavelengths sequentially emit light, and the light receiving portion receives the light emission output from the plurality of light emitting portions to detect the detection object. To do. The control unit takes in the light-receiving output from the light-receiving unit based on the light-emitting signal that causes the plurality of light-emitting units to sequentially emit light, and based on the comparison result of these light-receiving outputs, based on a preset value, the water content of the sensing object. When the image forming operation is started, the preset image forming condition is controlled based on the result of the judgment.

According to the second aspect of the present invention, the plurality of light emitting portions emit light of different wavelengths, and the light emission output from the plurality of light emitting portions is received by the light receiving portion. The plurality of light emitting units include a light emitting unit having a peak sensitivity at 1.45 μm on the long wavelength side of the spectral sensitivity of the light receiving unit and a light emitting unit having a peak sensitivity at 0.8 μm on the short wavelength side of the spectral sensitivity of the light receiving unit. However, the plurality of light emitting units and the light receiving units form a predetermined angle, and the outputs of the plurality of light emitting units and the light receiving units are set by external input.

According to the third aspect of the invention, the detection device detects the detection object at a predetermined position in the device, and the control unit outputs the data stored in the storage means from the detection device based on an internal preset time. In addition to updating with data, the image forming condition preset based on the data in the storage means is controlled based on the input signal for starting the image forming operation and the subsequent signal.

[0015]

FIG. 2 shows an embodiment of the present invention. This embodiment is an embodiment of the invention described in claims 1 to 3, and is an example of an image forming apparatus comprising an electrophotographic copying machine. The image carrier 11 made of a photoconductor is, for example, a photoconductor drum, and is rotationally driven by a motor during a copying operation to be uniformly charged by a charger 12 as a charging unit, and then exposed by an exposing unit to expose an input image. A latent image is formed. This electrostatic latent image is developed with a developer by the developing unit 13 and becomes a toner image. A developing bias voltage is applied to the developing unit 13 from a developing bias power source.

Further, the transfer sheet is fed to the registration roller 18 by the feeding signal from the control section in any one of the sheet feeding rollers 16 and 17 from the selected one of the sheet feeding devices having the sheet feeding trays 14 and 15. Then, the registration roller 18 sends the transfer paper in accordance with the toner image on the photosensitive drum 11. The transfer device 19 transfers the toner image on the photosensitive drum 11 to the transfer paper, and the fixing device 20 fixes the toner image on the transfer paper and discharges it to the discharge tray 21 as a copy. It is discharged to 22. The transfer paper after the front surface copy, which is discharged to the double-sided unit 22, is fed by the double-sided unit 22, the front side and the back side are reversed, and is conveyed to the registration roller 18, and the back side is transferred onto the photosensitive drum 11 by the transfer device 19 like the front side. After the toner image is transferred and the toner image is fixed by the fixing device 20, the toner image is ejected to the paper ejection tray 21 as a double-sided copy.

Such a copying operation is continuously repeated for the number of sheets set by the operation unit by inputting a start signal from a start switch for instructing the operation unit to start copying. The exposure means illuminates a document set on a document table and covered with a pressure plate with a light source for exposure and irradiates the photoconductor drum 11 with its reflected light through an optical system. An original image is exposed by scanning an original by moving an original scanning system which is a part of the system. The exposure means scans an original set on the original table and covered with a pressure plate with a scanner to read the read image signal, and the read image signal is processed by an image processing section and converted into an optical signal by an electro-optical conversion section. The original image may be exposed by irradiating the photosensitive drum.

A transfer belt 23 is used as the transfer device 19, and the transfer belt 23 is stretched around rollers 24 and 25 and driven to rotate. The transfer belt 23 is charged by the transfer / separation charger 26 and charged by the registration roller 18
The transfer paper is electrostatically adsorbed and conveyed, and the toner image on the photoconductor drum 11 is transferred to the transfer paper to separate the transfer paper from the photoconductor drum 11. The transfer paper on the transfer belt 23 is separated at the roller 24 by curvature separation by the waist of the transfer paper.

Further, heating devices 27 and 28 are provided at the bottoms of the paper feed trays 14 and 15, respectively.
Heats and dries (dehumidifies) the transfer paper in the paper feed trays 14 and 15. Above the paper feed trays 14 and 15, detection devices 29 and 30 for detecting the transfer paper in the paper feed trays 14 and 15 are arranged, and the paper feed trays 14 and 15 and the registration rollers 18 are provided.
Above the transfer paper transport path between the paper feed trays 14 and 15
A detection device 31 that detects a transfer sheet fed from the sheet to the registration roller 18 is arranged. A detection device 32 that detects the developer in the developing unit 13 is arranged above the developing unit 13.
A detection device 33 that detects the transfer paper on the transfer belt 23 is arranged above the roller 24.

FIG. 1 shows a part of the circuit configuration of this embodiment.
An input signal from each key of the operation unit is input to the control unit 34, which controls each unit of this embodiment such as the charging charger 12, the developing bias power source, the transfer / separation charger 26, and the heating devices 27 and 28. The detection device 29 has a plurality of light emitting units 35 and 36 and a single light receiving unit 37.
The light 36 irradiates the transfer paper 38 in the paper feed tray 14 serving as a detection object, and the reflected light is received by the light receiver 37.

As shown in FIG. 4, the light emitting section 35 should not be a light emitting source having a peak sensitivity at an emission wavelength of 1.45 μm, and the light emitting section 36 should be a light emitting source having a peak sensitivity at an emission wavelength of 0.8 μm. Has been done. The light emitting unit 36 may be a light emitting source having a peak sensitivity at an emission wavelength of 0.4 μm to 0.8 μm. The light receiving section 37 includes the light emitting sections 35 and 36.
A material having a sufficient sensitivity to light having an emission wavelength is used, for example, a material having a sensitivity to light having a wavelength of 0.7 μm to 1.7 μm is used. The light emitting units 35 and 36 are arranged so as to irradiate the detection object with light obliquely, and
The light receiving portion 37 is arranged at a position of 10 to 40 degrees on the normal line of the light emitting portions 35 and 36. The light emitting units 35 and 36 are the control unit 34.
3 is driven by a PWM (pulse width modulation) signal as shown in FIG. 3 to emit light, and the light receiving output of the light receiving unit 37 is amplified by the amplifier circuit 39 and input to the control unit 34.

Light emission output of the light emitting portions 35 and 36 and the light receiving portion 3
As a method of setting the light reception output of 7, the reference plate or the detection object is placed at the detection position of the detection object 38, and the light emitting units 35, 3
When controlling the amount of emitted light of No. 6, the control unit 34 performs PWM
The duty ratio of the signal is varied to adjust the output of the amplifier circuit 39 to a predetermined value. When the light emission amount (lighting interval) of the light emitting units 35 and 36 and the duty ratio of the PWM signal are kept constant, the control unit 34 controls a volume (electronic volume) (not shown) provided on the output terminal side of the light receiving unit 37 side. Adjust the value so that it can be changed and the received light output value is easy to handle for control purposes. The control unit 34 externally controls the light emission output of the light emitting units 35 and 36 and the light receiving unit 37 from outside by determining variations in the sensitivity of the light receiving unit 37 and removal of output noise with respect to deterioration of the emitted light amount of the light emitting units 35 and 36 and dirt. By adjusting the light reception output, it is possible to accurately detect the detection object.

The detection devices 30 to 33 are constructed in the same manner as the detection device 29, and each of the light emitting parts has a PW from the control part 34.
It is driven by the M signal to emit light, and the light receiving output of the light receiving unit is amplified by the amplifier circuit and input to the control unit. Further, in the detection devices 30 to 33, the light emission output of the light emitting unit and the light reception output of the light receiving unit are set similarly to the detection device 29. Detection device 29
Although the transfer paper detected by ~ 31 and 33 has a high reflectance, the developer and the transfer belt 23 detected by the detectors 32 and 33 have a low reflectance, so the detectors 32 and 33 emit and receive light from the light emitting unit. By adjusting the light receiving output of the light receiving unit, the light receiving output from the light receiving unit can be set to a value that can be processed as a control signal. The detection devices 29 to 33 are arranged at predetermined positions where the influence of ambient light, particularly near-infrared light, is small, and when there is a possibility of being affected by such influence, a protective member such as an outer case is arranged around the detection device.

FIG. 5 shows a processing flow of the control unit 34. When the power is turned on in step S1, the control unit 34 performs an initialization process in step S2 and detects the water content of the detection object in step S3. In the water content detection, the control unit 34 first detects the water content of the detection object such as transfer paper detected by the detection devices 29, 30, 32 in step S21 as shown in FIG. , 30 and 32, the PWM signal to one of the light emitting units (A light emitting unit) is turned on to cause the A light emitting unit to emit light, and in step S22, the light receiving output of the light receiving unit of each of the detection devices 29, 30, 32 is output. It is read through the amplifier circuit and it is judged whether or not the received light output is at a predetermined level. If the received light output is not at the predetermined level in each of the detection devices 29, 30, 32, in step S29 that detection device is selected. It is determined that there is no detection object such as transfer paper to be detected.

When the received light output is at a predetermined level, the control unit 34 determines in step S23 each of the detection devices 29, 30,
The light receiving output of the light receiving unit 32 is read through the amplifier circuit, the data (A data) of the light receiving output is sampled and stored in the storage unit in the control unit 34, and in step S24, the detection devices 29, 30, The other light-emitting unit (B
The PWM signal to the light emitting portion) is turned on to cause the B light emitting portion to emit light. Then, in step S26, the control unit 34 reads the light receiving output of the light receiving unit of each of the detection devices 29, 30, 32 through the amplifier circuit, determines whether the light receiving output is at a predetermined level, and performs each detection. If the received light output is not at a predetermined level in any of the devices 29, 30, 32, step S2
At 9, it is determined that there is no detection object such as a transfer paper detected by the detection device.

When the received light output is at a predetermined level, the control unit 34 determines the detection devices 29, 30,
The light receiving output of the light receiving unit 32 is read through the amplifier circuit, the data (B data) of these light receiving outputs are sampled and stored in the storage unit in the control unit 34, and in step S28, the detection devices 29, 30, The A data and the B data in the storage unit are compared for each 32, and the water content (moisture content) of the detected object is determined based on the comparison result and stored in the storage unit.

As shown in FIG. 5, the control unit 34 detects whether the pressure plate switch is turned on by the input signal from the pressure plate switch (SW) in step S4 after detecting the water content (water content) of the detection object in step S3. Detect whether or not. The pressure plate switch is a switch for detecting whether the pressure plate is covered with a document on the platen or raised from the platen, and the control unit 34 controls when the pressure plate is raised from the platen and the pressure plate switch is off. Returns to step S3.

Further, when the pressure plate is covered with the pressure plate switch and the pressure plate switch is turned on, the control unit 34 detects the size of the document on the platen in step S5 from the document size detecting means. Of the document size is detected by the input signal of step S6, and it is determined in step S6 whether or not the start switch is turned on by the input signal from the start switch. If the start switch is off, the process returns to step S3.

When the start switch is turned on, the control unit 34 selects the size of the transfer paper (paper) according to the original size in step S7 and selects the paper feed trays 14 and 15 in step S7.
Or one of the paper feed trays 14 and 15 is selected by a size selection signal from the operation unit, and copy scanning (movement of the document scanning system) is started in step S8.

Then, at the start of the copying operation, the control unit 34 sets the image forming condition (photosensitive drum) set in advance based on the data of the water content of the detection object (transfer paper, developer) stored in the storage unit. 11 charge potential, transfer / separation potential) are controlled. That is, in step S9, the control unit 34 controls the charger 12 based on the data of the water content (water content) of the developer detected by the detection device 31 in step S3 and stored in the storage unit in step S9. By controlling the charging potential of the photoconductor drum 11 in step S10 to cause the light emitting unit of the detection device 31 to emit light and monitor the input signal level input from the light receiving unit via the amplifier circuit, Detection device 3
After one passage is detected, the water content (water content) of the transfer paper is detected as shown in FIG. 6, and the data of the water content is stored in the storage unit. Next, the control unit 34 controls steps S11 and S1.
In step 2, the preset applied voltage (transfer / separation potential) of the transfer / separation charger 26 is detected based on the data of the water content (moisture content) of the transfer paper stored in the storage unit in step S10. Control.

Here, when the electrostatic latent image on the photosensitive drum 11 is developed, the moving amount of the toner moving from the developing section 13 to the photosensitive drum 11 is the charging potential of the charging charger 12 of the photosensitive drum 11, Changes in relation to the developing bias voltage applied from the developing bias power source to the developing unit 13,
When the developer contains a large amount of water, the toner movement amount tends to be small. Therefore, the control unit 34
Based on the data of the water content (water content) of the developer stored in the storage unit in step S9, it is determined whether or not the developer contains more water than the standard value, and the developer has more water than the standard value. If water is contained, the charging charger 12 is controlled to correct the charging potential of the photosensitive drum 11 to the negative side from the standard value, and in steps S11 and S12, step S11 is performed.
Based on the value of the water content (moisture content) of the transfer paper detected in 10, it is determined whether the transfer paper contains more water than the standard value, and the transfer paper contains more water than the standard value. If so, correct the transfer / separation potential to the plus side of the standard value.
The developing bias voltage may be controlled instead of controlling the charging potential of the photoconductor drum 11. In this case, the control unit 3
No. 4 corrects the developing bias voltage to the plus side of the standard value when the developer contains more water than the standard value.

After correcting the image forming conditions in this way, the control section 34 causes the copying operation to be performed as described above, and in step S13, it is judged whether or not the copying operation for the set number of sheets by the operating section is completed. If the set number of copy operations have not been completed, the process returns to step S3. In addition, the control unit 34
When the copy operation for the set number of sheets is completed, step S1
The post-processing is performed in step 4, and in step S15, the detection device 2
The heating devices 27 and 28 are controlled based on the data of the water content (moisture content) of the transfer paper which is detected in step S3 and stored in the storage unit by using 9, 30.

Next, the control section 34 judges whether or not the power source is turned off in step S16, and if the power source is not turned off, returns to step S3 and repeats the above-mentioned operation. Therefore, in each of the detection devices 29 to 33, the two light emitting units operate alternately based on the PWM signal from the control unit 34 for a predetermined time, and the light receiving output of the light receiving unit is input to the control unit 34 via the amplifier circuit. become. Further, the control unit 34 updates the data in the storage unit by the light reception output from the amplification circuit, and at the same time obtains the water content of the detection object from the light reception output from the amplification circuit as described above to obtain the water content data in the storage unit. And the image forming conditions are controlled based on the data in the storage unit based on the input signal from the start key of the operation unit or the signal thereafter.

Here, the control unit 34 controls the heating devices 27, 2
In the control of No. 8, the paper feed tray 14 stored in the storage unit is
The moisture content (moisture content) data of the transfer paper inside is compared with the set value to determine whether the data of the moisture content of the transfer paper in the paper feed tray 14 is larger than the set value. If the data is smaller than the set value, the moisture content of the transfer paper is 4-7.
%, The heating device 27 is turned off, and if the data of the moisture content of the transfer paper is larger than the set value, the heating device 2
Drying control is performed by turning on 7 to discharge the moisture of the transfer paper to the outside. This makes it possible to maintain the transfer paper in an optimal state without heating it unnecessarily.

Similarly, the control unit 34 compares the data of the water content (moisture content) of the transfer paper in the paper feed tray 15 stored in the storage unit with the set value and compares the transfer paper in the paper feed tray 15 with the set value. Judge whether the water content data of is larger than the set value,
When the data of the water content of the transfer paper is smaller than the set value, it is determined that the water content of the transfer paper is 4 to 7%, and the heating device 28 is used.
Is turned off, and when the data of the water content of the transfer paper is larger than the set value, the heating device 28 is turned on to discharge the water of the transfer paper to the outside, thereby performing a drying control.

In the control of the image forming conditions (charging potential of the photosensitive drum 11, transfer / separation potential), the control unit 34, as shown in FIG. The data of the water content of the transfer paper is read out, and it is determined in step S32 whether or not the data of the water content is within the control range. If the data of the water content is not within the control range, the operation unit is displayed in step S36. Display an error.

If the water content data is within the control range, the control unit 34 determines in step S33 whether or not the image forming condition should be corrected from the water content data.
If the image forming conditions should not be corrected, step S
At 35, the image forming condition is set to a preset standard value. If the image forming condition should be corrected, the control unit 34 corrects the image forming condition based on the water content data in step S34.

Further, the control section 34 controls the above step S10.
In the operation of, as shown in FIG. 8, first, in step S41, a paper feed signal is output to determine whether or not the transfer paper is fed from one of the paper feed trays 14 and 15, and when the paper feed signal is output. In step S42, a PWM signal is output to the light emitting unit of the detection device 31 to read the light reception output from the light reception unit of the detection device 31 through the amplifier circuit, and the level of the light reception output is monitored and the detection device 31 transfers the light. It is determined whether the leading edge of the paper has been detected. When the detection device 31 detects the leading edge of the transfer paper, the control unit 34 uses the detection device 31 in step S43 to detect the water content of the transfer paper as shown in FIG.

In this embodiment, in an image forming apparatus composed of a copying machine for forming an image corresponding to an input image (original image) on a recording medium composed of a transfer paper, a developer and a transfer device are arranged at predetermined positions in the apparatus. A plurality of light emitting parts with different emission wavelengths, which detect a detection object made of paper and sequentially emit light,
And detecting devices 29 to 33 each having a light receiving unit for receiving the light emission output from the plurality of light emitting units, and receiving the light reception output from the light receiving unit based on a light emission signal for sequentially causing the plurality of light emitting units to emit light. The water content of the sensing object is determined based on a preset value from the comparison result of these received light outputs, and the preset image is determined based on the result of the determination at the start of the image forming operation (copying operation). Since the control unit 34 for controlling the forming condition is provided, the image forming condition can be stably and optimally controlled even if the environment changes by directly detecting the water content of the detection object by the detecting device. The quality can be improved. Further, by turning on / off the heating devices 27 and 28 in accordance with the amount of moisture of the transfer paper in the paper feed trays 14 and 15 detected by the detection devices 29 and 30, it is possible to eliminate waste of power.

Further, the detection device includes a plurality of light emitting portions having different emission wavelengths and a light receiving portion for receiving light emission output from the plurality of light emitting portions, and the plurality of light emitting portions have the spectral sensitivity of the light receiving portion. A light emitting portion having a peak sensitivity at 1.45 μm on the long wavelength side and 0.8 μm on the short wavelength side of the spectral sensitivity of the light receiving portion.
A light emitting section having a peak sensitivity, the plurality of light emitting sections and the light receiving section are arranged at a predetermined angle, and the outputs of the plurality of light emitting sections and the light receiving section can be set by an external input. Therefore, it is not necessary to replace the filter, it takes no time to detect the detection object, and it is not necessary to provide the filter for each detection wavelength, so that the cost and size can be reduced.

Further, in an image forming apparatus composed of a copying machine for forming an image corresponding to an input image (original image) on a recording medium made of transfer paper, a detection device arranged at a predetermined position in the apparatus to detect a detection object. And updating the storage data of the storage means for storing the data from the detection device with the data from the detection device based on an internal preset time, and inputting the image forming operation start signal and subsequent signals. The image forming condition is controlled by directly detecting the detection object with the detecting device, since the control unit 34 controls the image forming condition set in advance based on the data in the storage means based on the above. As a result, even if the environment changes, the image forming conditions can be stably and optimally controlled, and the image quality can be improved. The present invention is not limited to the above embodiment, but can be applied to an image forming apparatus such as a facsimile or a printer.

[0042]

As described above, according to the first aspect of the invention, in an image forming apparatus for forming an image corresponding to an input image on a recording medium, the object is detected at a predetermined position in the apparatus. A detection device having a plurality of light emitting portions having different emission wavelengths, which sequentially perform a light emitting operation, and a light receiving portion for receiving a light emission output from the plurality of light emitting portions, and a light emission signal for causing the plurality of light emitting portions to sequentially perform a light emitting operation. Data of the light receiving output from the light receiving unit based on the above, and the water content of the detected object is determined based on a preset value from the comparison result of these data, and the determination is made at the start of the image forming operation. Since a control unit for controlling preset image forming conditions based on the result is provided, it is possible to stably and optimally control the image forming conditions even when the environment changes, and it is possible to improve the image quality. .

According to the second aspect of the present invention, it is provided with a plurality of light emitting portions having different emission wavelengths and a light receiving portion for receiving the light emission output from the plurality of light emitting portions, and the plurality of light emitting portions are the light receiving portions. Of the plurality of light-emissions having a peak sensitivity at 1.45 μm on the long wavelength side of the spectral sensitivity of 1. And the light receiving unit are arranged at a predetermined angle, and the outputs of the plurality of light emitting units and the light receiving unit can be set by an external input, so that it is not necessary to replace the filter to detect a detection object. It does not take time, and it is not necessary to provide it for each detection wavelength, so that cost reduction and downsizing can be achieved.

According to the third aspect of the invention, in an image forming apparatus for forming an image corresponding to an input image on a recording medium, a detecting apparatus arranged at a predetermined position in the apparatus and detecting a detection object, and the detection apparatus are provided. The storage data of the storage means for storing the data from the device is updated with the data from the detection device based on an internal preset time, and the data is stored based on the input signal for starting the image forming operation and the subsequent signal. Since a control unit for controlling preset image forming conditions based on the data in the storage means is provided, even if the environment changes, the image forming conditions are stably and optimally controlled to improve the image quality. It is possible to plan.

[Brief description of drawings]

FIG. 1 is a block diagram showing a part of an embodiment of the present invention.

FIG. 2 is a sectional view showing the outline of the embodiment.

FIG. 3 is a waveform diagram showing an example of a PWM signal in the example.

FIG. 4 is a characteristic curve diagram showing sensitivities of a light emitting unit and a light receiving unit of the detection device in the example.

FIG. 5 is a flowchart showing a processing flow of a control unit in the embodiment.

FIG. 6 is a flowchart showing in detail a part of the processing flow.

FIG. 7 is a flowchart showing another part of the processing flow in detail.

FIG. 8 is a flowchart showing another part of the processing flow in detail.

[Explanation of symbols]

 29-33 Detection device 34 Control part 35,36 Light emitting part 37 Light receiving part

Claims (3)

[Claims] 1. An image forming apparatus for forming an image corresponding to an input image on a recording medium, wherein a plurality of light emitting devices having different emission wavelengths are arranged at predetermined positions in the device, detect a detection object, and sequentially emit light. And a detection device having a light receiving section for receiving the light emission output from the plurality of light emitting sections, and receiving the light reception output from the light receiving section based on a light emission signal for causing the plurality of light emitting sections to sequentially emit light. The water content of the sensing object is determined based on a preset value from the comparison result of the received light output of the, and the preset image forming condition is controlled based on the result of the determination at the start of the image forming operation. An image forming apparatus comprising: a control unit. 2. A plurality of light emitting sections having different light emission wavelengths, and a light receiving section for receiving light emission output from the plurality of light emitting sections,
The plurality of light emitting units have a peak sensitivity at 1.45 μm on the long wavelength side of the spectral sensitivity of the light receiving unit and a light emitting unit having a peak sensitivity at 0.8 μm on the short wavelength side of the spectral sensitivity of the light receiving unit. And a plurality of light emitting units and the light receiving unit are arranged at a predetermined angle, and outputs of the plurality of light emitting units and the light receiving unit can be set by an external input. . 3. An image forming apparatus for forming an image corresponding to an input image on a recording medium, a detecting apparatus arranged at a predetermined position in the apparatus to detect a detected object, and a memory for storing data from the detecting apparatus. The data stored in the storage unit is updated with the data from the detection device based on an internal preset time, and the data in the storage unit is generated based on the input signal for starting the image forming operation and the subsequent signal. An image forming apparatus, comprising: a control unit that controls image forming conditions set in advance.