JP2000231255A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable carrying out of toner concentration detection and adjustment of the toner concn. to be performed all the times by providing a T sensor for each developing unit inside a revolver developing unit, transmitting optical signals between a main body side and the revolver developing unit and supplying power from the device main body side by a current transformer. SOLUTION: In the image forming device, the T sensors are provided for each developing device inside the revolver developing unit, optical signals are transmitted between the main body side and the revolver developing unit and furthermore, power is supplied from the main body side to the revolver developing unit by the current transformer. Thus, a sensor value is read from each developing device when necessary and the adjustment of the toner density can be carried out when necessary. In this device, the developing devices of 4 colors 115 to 118 are installed inside the revolver developing unit 110 and electrical load for a secondary side connection unit and T sensors detecting toner concn. provided to each of the 4 color developing devices and a toner replenishing device is provided.

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 a revolver developing unit for integrally rotating a plurality of developing units.

[0002]

2. Description of the Related Art In an image forming apparatus using a two-component developer composed of a toner and a carrier, a T sensor for detecting a toner density for adjusting a toner density in a developing unit to a predetermined value is used. . Conventionally, such toner density detection has been configured and performed as shown in FIG.

In FIG. 11, reference numeral 200 denotes a rotating housing which is rotatably supported and has a plurality of developing units 201 to 204 therein.
And a developing point P facing the photosensitive drum 205
The plurality of developing devices 201 to 204 are selectively rotated and moved. Light from a light source 211 on the copying machine main body side is guided to a developing roll surface of each of the developing devices 201 to 204 by a first optical fiber 212, and the reflected light is guided to a light receiving element 214 by a second optical fiber 213 to obtain a toner density. Was detected.

[0004]

In the conventional apparatus, the toner density can be detected only in the developing device located at a position facing the developing point P, but the toner density in other developing devices can be detected. could not.

For this reason, when developing using the selected developing device, the selected developing device is rotated to the developing point P to detect the toner density, and when the toner density is not the predetermined value, the predetermined value is set. , And the development is started after a predetermined time, so that it takes a long time to start the development.

According to the present invention, the toner concentration can be detected at any time,
It is an object to provide an image forming apparatus including a revolver developing unit capable of adjusting a toner concentration to a predetermined value.

[0007]

According to a first aspect of the present invention, there is provided an image forming apparatus having a revolver developing unit for integrally rotating a plurality of developing units. A T sensor provided for each developing device, a reading command unit for reading outputs of the plurality of T sensors and supplying toner to the plurality of developing devices, an image forming apparatus main body and the reading device An optical communication transmission / reception means for performing a signal between the light source and the command means, and power from the image forming apparatus main body to at least the T sensor of the revolver developing unit, the reading instruction means, and the optical communication transmission / reception means by a current transformer Power supply means for supplying.

According to the second aspect of the present invention, the optical communication transmission / reception means is opposed to the optical communication transmission / reception means on the image forming apparatus main body side when the revolver developing unit stops at the developing position. According to the third aspect of the present invention, the communication transmitting / receiving means is located on a rotation axis of the revolver developing unit.

According to a fourth aspect of the present invention, when the revolver developing unit stops at the developing position, the power transfer means faces the power transfer means on the image forming apparatus main body side. Further, in the invention according to claim 5, the current transformer of the power transfer means is disposed in a ring shape around a rotation axis of the revolver developing unit.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a full-color electrophotographic copying machine to which the present invention is applied will be described. FIG. 1 is a schematic configuration diagram of a main part of the printer unit according to the first embodiment. The printer unit is provided with a photoreceptor drum 10 as an image carrier. Around the photoreceptor drum, a writing optical unit as an exposure unit (not shown) and a photoreceptor cleaning device 111 as a cleaning unit When,
A charging charger 13 as charging means, and a revolver developing unit 110 which is a rotary developing device as developing means
And an intermediate transfer unit 120 as an intermediate transfer unit. The printer unit also includes a transfer unit 130 as a transfer unit, a fixing unit 145 as a fixing unit, and a paper supply unit and a control unit (not shown) similar to those in the first embodiment.

The photoconductor cleaning device 111 includes a fur brush 111 b and a photoconductor cleaning blade 11.
1c to clean the surface of the photosensitive drum 10 after the primary transfer. Further, the fixing unit 145 includes:
It has a fixing roller pair 145a and a discharge roller pair (not shown).

A solid lubricant 111d as a lubricant is disposed around the fur brush 111b so as to contact the tip of the brush. This solid lubricant 111d
As in the first embodiment, for example, zinc stearate composed of fine particles molded into a plate shape can be used.

The revolver developing unit 110 has a Bk
Developing unit 115, C developing unit 116, and M developing unit 117
And a Y developing device 118, and by rotating the revolver developing unit, a developing position of the developing device of each color which faces the photosensitive drum 10 can be determined.

The intermediate transfer unit 120 includes an intermediate transfer belt 121 as an intermediate transfer member, a primary transfer bias roller 122 as a charge applying means, a primary transfer power supply 128 as a power supply connected thereto, and a primary transfer power supply 128 as a power supply. An earth roller 123 as a pre-transfer charge removing unit, a driving roller 124 as a belt driving unit, a tension roller 125,
The configuration is such that the secondary transfer opposing roller 126 and the cleaning opposing roller 127 are stretched.

All the rollers that are stretched over the intermediate transfer belt 121 are made of a conductive material, and each roller other than the primary transfer bias roller 122 is grounded. The primary transfer bias roller 122 includes
A primary transfer power supply 128 supplies a predetermined primary transfer bias controlled by a constant current or a constant voltage.

The intermediate transfer belt 121 has the same structure as that of the first embodiment, but is formed so that its volume resistivity is 10 ¹² to 10 ¹⁴ Ωcm, preferably 10 ¹³ Ωcm. . Further, the surface resistivity of the intermediate transfer belt 121 on the surface layer side is configured to be 10 ⁷ to 10 ¹⁴ Ωcm.

A lubricant applying brush 129a as a lubricant applying means is provided around the intermediate transfer belt 121.
, A belt cleaning blade 129b, and a transfer unit 130, which can be moved toward and away from the intermediate transfer belt 121 by a contact / separation mechanism (not shown).

The transfer unit 130 includes a secondary transfer belt 134 as a transfer material carrier and a transfer cleaning blade 132 for cleaning the surface of the secondary transfer belt.
, A secondary transfer bias roller 131 facing the secondary transfer facing roller 126 of the intermediate transfer unit 120, a secondary transfer power supply 139 connected to the secondary transfer bias roller 131, and a first support located at an end on the paper feed unit side. Roller 135a and fixing unit 1
There is a second support roller 135b located at the end on the 45 side, a third support roller 135c facing the transfer cleaning blade 132, a transfer paper charge removal charger 136, and a transfer belt charge removal charger 137.

The secondary transfer belt 134 is formed of PVDF so as to have a high volume resistivity of 10 ¹³ Ωcm or more. Note that the transfer unit 130 is not limited to this configuration.
It is also possible to adopt a configuration in which a member having another shape such as a drum is applied instead of.

Next, the operation of the copying machine when the order of development is Bk, C, M, and Y will be described. Before starting the image forming cycle, the photosensitive drum 10 is rotationally driven in the direction of arrow C in FIG. 1, that is, counterclockwise, and the charging charger 113 starts corona discharge. At this time, for example, the photosensitive drum 10 is uniformly charged to a predetermined potential with a negative charge. The intermediate transfer belt 121 of the intermediate transfer unit 120 is driven at the same speed as the photosensitive drum 10, and rotates in the direction of arrow D in FIG. 1, that is, clockwise.

In the scanner section, as in the first embodiment, color image information of a document is read at a predetermined timing, and a laser beam is written by the writing optical unit based on Bk image data obtained from the image information. Optical writing (for example, raster exposure) with light is performed. Thereby, the B corresponding to the Bk image data is displayed on the photosensitive drum 10.
A k latent image is formed. Thereafter, the Bk latent image formed on the photosensitive drum 10 is transferred to the revolver developing unit 110.
Is reversely developed with negatively charged toner. As a result, a Bk toner image is formed on the photosensitive drum 10.

The Bk toner image thus formed on the photosensitive drum 10 is primarily transferred to the surface of the intermediate transfer belt 121 by the transfer electric field in the primary transfer area. This transfer electric field is formed by electric charges applied to the intermediate transfer belt 121 by the primary transfer bias roller 122.

At this time, the primary transfer bias roller 1
22, the primary transfer power supply 128, for example,
1.5 kV for the first color Bk toner image, C for the second color
1.6 to 1.8 kV for the toner image, 1.8 to 2.0 kV for the M toner image of the third color, and an appropriate magnitude of 2.0 to 2.2 kV for the Y toner image of the fourth color A primary transfer bias is applied. After the development, the photosensitive drum 10
The primary transfer residual toner remaining on the photosensitive drum is removed from the photosensitive drum by the photosensitive member cleaning device 111.

The image surface on the intermediate transfer belt 121 on which the Bk toner image has been primarily transferred is returned to the primary transfer area again, as in the first embodiment. At this time, similarly to the first embodiment, the lubricant application brush 129a and the belt cleaning blade 129b are separated from the intermediate transfer belt 121 by the respective contact / separation mechanisms so that the toner image is not disturbed.

Further, the first support roller 135a and the secondary transfer bias roller 13 in the transfer unit 130
1 is moved by a transfer contact / separation mechanism (not shown),
The next transfer bias roller is separated from the intermediate transfer belt 121. At this time, the secondary transfer bias roller 1
The application of voltage by the secondary transfer power supply 139 connected to 31 is stopped. The above state is maintained until the toner image primarily transferred on the intermediate transfer belt 121 is secondarily transferred onto transfer paper.

On the other hand, after the above-described Bk process is completed, the C process is started on the photosensitive drum 10 side, and the color image information of the original is read again at a predetermined timing, and the C image data obtained from this image information is read. , A C latent image is formed on the photosensitive drum 10 by a laser beam, and a C toner image is formed by a C developing device 116.

In this embodiment, the rotation of the revolver developing unit 110 is started immediately after the trailing end portion of the Bk latent image has passed. This rotation operation is completed before the leading end portion of the C latent image formed on the photosensitive drum 10 reaches the developing position of the C developing device 116. As a result, the C developing device 116 is positioned at the developing position, and the C developing device moving to this developing position is
Develop with toner.

Thereafter, in the M step and the Y step, as in the above-mentioned C step, latent image formation, development, and primary transfer are performed based on the respective image data. In this way, on the same image surface on the intermediate transfer belt 121,
Bk, C, sequentially formed on the photosensitive drum 10
The primary transfer of each of the M and Y toner images forms a toner image in which these four colors overlap on the intermediate transfer belt.

The toner image transferred on the intermediate transfer belt 121 as described above is sent to the secondary transfer area for secondary transfer onto the transfer paper 100. At this time, the secondary transfer bias roller 131 of the transfer unit 130
Is pressed against the intermediate transfer belt 121 by a transfer contact / separation mechanism (not shown). Thereafter, a predetermined secondary transfer bias is applied to the secondary transfer bias roller 131 to form a secondary transfer electric field in the secondary transfer area.

Thus, the toner image on the intermediate transfer belt 121 is transferred onto the transfer paper 100. Also,
The transfer paper 100 conveyed to the secondary transfer area is fed at the timing when the leading end of the toner image on the intermediate transfer belt 121 reaches the secondary transfer area.

As described above, the intermediate transfer belt 121
The transfer paper 100 on which the toner images formed by overlapping the four colors are collectively transferred is then transferred to the transfer unit 13.
At 0, the sheet is conveyed to a portion opposite to the transfer sheet discharging charger 136. When passing through the facing portion, the transfer paper is
The transfer paper is neutralized by the transfer paper neutralization charger 136 in the operating state, and is separated from the secondary transfer belt 134. Then, the separated transfer paper is sent between the rollers of the fixing roller pair 145a of the fixing unit 145.

In the fixing roller pair 145a, an unfixed toner image on the transfer paper 100 is melted in a fixing area formed by a nip formed between the rollers, and the unfixed toner image is fixed. Then, the transfer paper is carried out to a copy tray (not shown) and stacked.

On the other hand, the intermediate transfer belt 121 after the secondary transfer
The belt cleaning blade 129b presses the intermediate transfer belt 121 by a belt cleaning contact / separation mechanism (not shown) to remove the secondary transfer residual toner remaining on the surface of the intermediate transfer belt 121. Further, in order to improve the cleaning property and the secondary transfer property, the lubricant accommodated in the lubricant accommodating portion 129c by the lubricant applying brush 129a pressed against the intermediate transfer belt 121 by a contact / separation mechanism (not shown). Is applied. As the lubricant, for example, zinc stearate composed of plate-shaped fine particles can be used.

After the transfer paper is peeled off, the charge remaining on the surface of the secondary transfer belt 134 is discharged by the transfer belt discharging charger 137. The surface of the secondary transfer belt 134 is further cleaned by the belt cleaning blade 129b.

FIG. 2 is a schematic configuration diagram of a main part of a printer unit according to a second embodiment, and the same reference numerals are given to the same components as those in the first embodiment. This copier mainly aims at cost reduction, and the structure and operation of the printer section are only slightly different from those of the first embodiment. Therefore, the copier is configured in the same manner as the first embodiment. The description of the operating part will be omitted.

In this embodiment, the intermediate layer of the intermediate transfer belt 221 in the intermediate transfer unit 220 is a medium resistance layer having a volume resistivity of 10 ⁸ to 10 ¹¹ Ωcm. Further, the intermediate transfer belt 221 has 10 ¹⁰
It has a volume resistivity of 〜１０10 ¹² Ωcm. The surface resistivity of the intermediate transfer belt 221 on the surface layer side is:
It is configured to be 10 ⁷ to 10 ¹⁴ Ωcm. By using the intermediate transfer belt 221 having such a medium resistance,
It is possible to prevent charging unevenness occurring on the surface of the intermediate transfer belt 221 after the primary transfer.

In the present embodiment, the drive roller 224 in the intermediate transfer unit 220 is disposed downstream of the secondary transfer area in the belt rotation direction and upstream of the primary transfer area in the belt rotation direction. Then, the belt cleaning blade 1 is opposed to the driving roller 224.
By arranging 29b, the drive roller also serves as the cleaning opposing roller 127 in the second embodiment.

In the present embodiment, the transfer unit is replaced by the secondary transfer opposing roller 12 of the intermediate transfer unit 220 instead of the transfer unit of the first embodiment.
6 is used. Accordingly, the number of components required for the secondary transfer process is reduced, and the cost can be reduced as compared with the first embodiment.

At the time of paper feeding in the present embodiment, the fed transfer paper 100 is directly sandwiched between the secondary transfer bias roller 231 and the intermediate transfer belt 221, and the transfer paper 100 of the fixing roller pair 145 a of the fixing unit 145 is formed. It is sent between the rollers.

Next, an embodiment of the present invention will be described with reference to FIGS. FIG. 3 is a block diagram showing a configuration example for supplying power and transmitting signals between the image forming apparatus main body and the revolver developing unit 110 in a non-contact manner. As shown in this figure, connection units 2 and 12 are provided in the main body system 1 and the revolver developing unit 110. This connection unit is a unit configured to transfer power and a control signal from the main body 1 to the revolver side in a non-contact manner. The connection unit is a pair of the main body side and the revolver side, and is attached to the main body side. One thing
The secondary side is the one mounted on the secondary side and the revolver side. Note that DC power is supplied to the connection unit 2 on the primary side from a power supply 4 disposed in the main body 1.

The main control CPU 3 in the main body 1 is a CPU for controlling the main body system and generates a load control signal for controlling the load in the revolver developing unit 110. Also, it receives a signal fed back from the load.

In the revolver developing unit 110, FIG.
In addition to the four-color developing units 115 to 118 described above, the secondary-side connection unit 12 and the four-color developing units 11
There are provided a T sensor (not shown) for detecting the toner density provided at each of the reference numerals 5 to 118, and electric loads 13a, b, c, d of the toner replenishing device.

Main body system and revolver developing unit 11
During the period of 0, a power source (electric power) is supplied to the revolver developing unit 110 in a non-contact manner, and the electric loads 13a to 13d in the revolver developing unit 110 are driven using the power,
The main control CPU 3 can control devices in the revolver and obtain information in the revolver.

FIG. 4 conceptually shows the structure of a current transformer which is power transfer means for supplying power to the revolver developing unit 110 in the connection unit.

In FIG. 4, the primary side connection unit 2 and the secondary side connection unit 12 have coils 6, 14 respectively.
Are laid out at opposing positions. The coil 6 on the primary side is provided with a power supply circuit 5. The power supply circuit 5 is a circuit that performs chopping control and the like for more efficiently generating an electromagnetic force toward the secondary side.
DC power is supplied from a power supply 4 in the main body.

When a current flows through the primary coil 6, an electromagnetic force is generated in the coil. The opposed secondary coil 14 receives the electromagnetic force generated on the primary side, and as a result, electromotive force is generated at both ends of the secondary coil 14. In order to further stabilize the generated electromotive force, a voltage stabilizing circuit (secondary output stabilizing circuit) 15 is attached to the secondary coil 14, and the stabilized power is supplied to the electric load 13. They are driven. The primary side coil 6 is fixed to the image forming apparatus main body 1, and the secondary side coil 14
Is fixed to the revolver developing unit 110 and rotates together with the revolver developing unit 110.

FIG. 5 is a block diagram showing a configuration in the case where optical communication is used for signal transfer in the connection unit. As shown in this figure, the primary side connection unit 2
The optical communication unit (optical communication transmitting / receiving unit) 8 and the power transmitting unit 7 are provided, and the secondary side connection unit 11 is provided with the optical communication unit (optical communication transmitting / receiving unit) 18 and the power receiving unit 17.

The optical communication sections 8 and 18 have a light emitting section and a light receiving section on both the primary side and the secondary side, and when one side emits light, the other side receives the light. An LED can be used for the light emitting unit, and a phototransistor can be used for the light receiving unit.

The control signal transmitted by serial communication from the main control CPU 3 is transmitted to the primary side optical communication transmitting / receiving section 8.
Converts the light into an optical signal, and causes the light emitting unit to emit light based on the signal. The secondary-side optical communication transmission / reception unit 18 receives the primary-side light emitted by the light-receiving unit and converts it into an electric signal. The converted signal is transmitted by a load control CPU 16 provided in the revolver developing unit 110, and the CPU 16 controls the electric load 13 based on the received signal.

A feedback signal from the electric load 13 is input to the load control CPU 16, and the signal is converted into an optical signal by the optical communication transmitting / receiving section 18 as serial communication and transmitted toward the primary side. The primary-side optical communication transmitting / receiving unit 8 receives the light at the light receiving unit, converts the light into an electric signal, and transmits the electric signal to the main control CPU 3.

In this manner, the main system 1 (main control CPU 3) can receive the information on the electric load of the developing revolver laid out in a non-contact manner with the main body 1, and can be laid out in a non-contact manner. This makes it possible to control the electrical load of the developed revolver.

Now, as described above, the current transformer,
The connection units 2 and 12 using optical communication or the like enable power supply and signal transmission between the main system 1 and the revolver developing unit 110. In the present embodiment, as shown in FIG. 6, one optical communication transceiver 8 is provided in the connection unit 2 on the main body side, and four optical communication transceivers 18a to 18d are provided in the connection unit 12 on the revolver side. I have. The connection unit 12 on the revolver side is provided at the center of the developing revolver, and the four optical communication transmitting / receiving units 18a to 18d are laid out at the same distance from the revolver rotation axis and at 90 ° positions. The distance of the transmitting / receiving section 8 on the main body side from the revolver rotation axis is equal to the distance of the transmitting / receiving sections 18a to 18d on the revolver side from the revolver rotation axis. The position of each transmitting / receiving section is determined such that the transmitting / receiving section 8 on the main body side and one of the transmitting / receiving sections 18 on the revolver side face each other at the stop position of the revolver.

In the present embodiment, in the revolver, four color (four) developing units are mutually 90 degrees with respect to the revolver rotation axis.
When the color developing units are switched, the revolver developing unit 110 is rotated at a multiple of 90 degrees. Thus, when the four color developing units are switched, when the revolver developing unit 110 stops at the image forming position (developing position), the four optical communication transmitting / receiving units 1
One of 8a to 8d always comes to a position facing the transmitting / receiving section 8 on the main body side. Therefore, transmission / reception of optical communication can be performed by the transmission / reception unit 8 on the main body side and one of the transmission / reception units 18 on the revolver side opposed thereto. Therefore, a reliable signal can be transmitted between the main body system 1 and the revolver developing unit 110.

Now, in FIG. 6, the transmitting / receiving section 8 on the main body side and the transmitting / receiving section 18a on the revolver side are opposed to each other. 8 and transmission / reception unit 18b on the revolver side
Are opposed to each other. Similarly, each time the development revolver is rotated to switch the development color, one of the four optical communication transmission / reception units 18a to 18d and the transmission / reception unit 8 on the main body side transmit a signal. it can.

As described above, the electric load in the developing revolver is a T sensor for detecting the toner concentration in the developing device and a toner replenishing device. It goes without saying that control is possible.

Also, as for the power transfer unit described as the current transformer in FIG. 4, one power transmission unit 7 is provided in the connection unit 2 on the main body side and the connection on the revolver side, similarly to the optical communication transmission and reception unit in FIG. By providing the four power receiving units 17 in the unit 12 (the positional relationship is the same as that of the optical communication transmitting / receiving unit), stable power supply can always be performed between the main system 1 and the revolver developing unit 110.

In the example shown in FIG. 6, one optical communication transmitting / receiving unit is provided on the primary side (main unit side), four optical communication transmitting / receiving units are provided on the secondary side (revolver side), and one power transmitting unit is provided on the main unit side. Although four power receiving units are provided on the revolver side,
One optical communication transmitting / receiving unit may be provided on the revolver side, four power transmitting units may be provided on the main body side, and one power receiving unit may be provided on the revolver side.

As shown in FIG. 7, four optical communication transmitting / receiving sections 8a to 8d and 1 are provided on both the main body side and the revolver side.
8a to 8d may be provided. In this figure, the optical communication transmitting and receiving unit is described, but similarly, 4
One power transmission unit and four power reception units on the revolver side can be provided.

Alternatively, if one optical communication transmitting / receiving unit is provided on the revolver side, four power transmitting units are provided on the main unit side, and one power receiving unit is provided on the revolver side, the connection unit Can be reduced in size.

Here, in order to provide the image forming apparatus of the embodiment with four (four color) developing units (in this case, usually, to rotate and stop the developing revolver at a multiple of 90 degrees). The number of optical communication transmitting / receiving units, power transmitting units, or receiving units provided in the connection unit 12 on the main body side and / or the revolver side is four. However, when three (three color) developing units are provided, It is sufficient to provide three optical communication transmission / reception units and a power transfer unit in the connection unit 12 on the side of (or) the revolver. The number of optical communication transmission / reception units and power delivery units provided is not limited to four or three. If the revolver can be placed at a position facing each other when the revolver is stopped, the communication unit (optical communication transmission / reception unit or power delivery unit) Any number is acceptable.

Further, in the example shown in FIGS. 6 and 7, the connection units 2 and 12 are formed in a cylindrical shape, and the communication unit is arranged in a cross-sectional view of the cylinder.
When the connection unit has a cylindrical shape, those communication units can be arranged on the peripheral surface of the cylinder. Even in this case,
When the revolver is stopped, the layout may be such that the respective communication sections on the main body side and the revolver side face each other.

Next, another embodiment of the present invention will be described. As shown in FIG. 9, one optical communication transmitting / receiving unit 8 is provided at the center (on the revolver rotation axis) of the connection unit 2 on the main body side, and one optical communication transmitting / receiving unit 8 is also provided at the center (on the revolver rotation axis) of the connection unit 12 on the revolver side. An optical communication transceiver 18 is provided.
Thereby, signals can be transmitted to the main body side and the revolver side by one transmitting / receiving unit. In the case of this embodiment, regardless of whether the developing revolver is rotating or stopped,
Since the communication unit always faces, signals can be exchanged between the main unit and the revolver at any time. Therefore, reliable signal transmission can always be performed.

Although not shown, one power transmission unit 7 is provided at the center (on the rotation axis of the revolver) of the connection unit 2 on the main body side, similarly to the optical communication transmission / reception unit. By providing one power receiving unit 17 at the center (on the rotation axis of the revolver), the power transfer unit always faces the developing revolver irrespective of whether the developing revolver is rotating or stopped. It becomes possible to supply. Further, the load in the revolver can be driven at any time. For example, the CPU in the revolver can be operated to perform calculations and the like as necessary.

Next, still another embodiment of the present invention will be described. As shown in FIG. 9, in the present embodiment, one optical communication transmitting / receiving unit 8 is provided at the center (on the revolver rotation axis) of the connection unit 2 on the main body side, and the connection unit 1 on the revolver side is provided.
One optical communication transmitting / receiving unit 18 is also provided at the center of the two (on the rotation axis of the revolver). Then, the optical communication transmitting / receiving unit 8,
A ring-shaped power transfer unit, that is, a power transmission unit 7 on the main body side and a power reception unit 17 on the revolver side are arranged outside the power supply unit 18. Since the ring-shaped power transfer unit is always located at the opposite position even during rotation of the revolver, it is possible to constantly supply power from the main body to the revolver.
Further, since the transmitting / receiving section of the optical communication is always located at the opposite position, it is possible to always transmit / receive a signal. Therefore, reliable signal transmission and reception and stable power supply can be performed at any time.

In order to make the power transfer section ring-shaped, the core can be formed in a ring shape and a coil can be wound around the ring-shaped core.

By the way, the ring-shaped power transfer portion has a property that, when the center thereof is shifted, the power supply efficiency is reduced accordingly. The graph of FIG. 10 shows the relationship between the center shift amount and the power efficiency. Also, in the optical communication transmitting / receiving unit, if the opposing center is shifted, the quality of communication deteriorates.

Therefore, by arranging the optical communication transmission / reception units 8 and 18 and the power transmission / reception units 7 and 17 concentrically around the revolver rotation axis, communication quality and power supply efficiency can be optimized. Reliable signal transmission and more stable power supply can be performed.

In FIGS. 6 to 9, the connection unit is described as having a cylindrical shape, but the shape of the connection unit is not limited to this. Similarly, the optical communication transmitting / receiving unit has been described as being cylindrical, but this is a shape for convenience, and the shape of the optical communication transmitting / receiving unit or the power transmitting / receiving unit is not limited.

Although the T sensor has been described as an example of the electric load in the developing revolver, it is needless to say that the present invention is useful for exchanging signals with other sensors or switches. Alternatively, the present invention can be applied to driving and controlling a motor and the like disposed in the revolver.

The present invention can also be applied to a case where the developing device mounted on the developing revolver is a one-component developing device, and can perform reliable signal transmission and stable power transfer.

[0071]

As described above, a T sensor is provided for each developing unit in the revolver developing unit, a signal is transmitted between the main unit and the revolver developing unit by light, and a signal is transmitted from the main unit to the revolver developing unit. Since the power is supplied by the current transformer, the sensor value can be read from each developing unit at a necessary time, and the toner density can be adjusted at the necessary time.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a main part in a printer unit according to a first embodiment to which the present invention is applied.

FIG. 2 is a schematic configuration diagram of a main part of a printer unit according to a second embodiment to which the present invention is applied.

FIG. 3 is a block diagram illustrating a configuration example for supplying power and transmitting signals between an image forming apparatus main body and a developing revolver in a non-contact manner.

FIG. 4 is a schematic diagram conceptually showing a configuration of a current transformer for supplying electric power to a developing revolver side.

FIG. 5 is a block diagram showing a configuration in a case where optical communication is used for signal transmission between a main body and a developing revolver.

FIG. 6 is a perspective view showing a layout of an optical communication transmitting / receiving unit on a connection unit in the embodiment.

FIG. 7 is a perspective view showing another example of the layout of the optical communication transmitting / receiving unit on the connection unit.

FIG. 8 is a perspective view showing a layout of an optical communication transmitting / receiving unit on a connection unit in another embodiment of the present invention.

FIG. 9 is a perspective view showing a layout of an optical communication transmitting / receiving unit and a power transfer unit on a connection unit in still another embodiment of the present invention.

FIG. 10 is a graph showing a relationship between a center shift amount and power efficiency in a ring-shaped power transfer unit.

FIG. 11 is an explanatory diagram of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image forming apparatus main body 2 Connection unit primary side 3 Main control CPU 4 DC power supply 6, 14 Coil 7 Power transmission unit 8, 18 Optical communication transmission / reception unit 12 Connection unit secondary side 13, 13a, 13b, 13c, 13d Electrical Load 17 Power receiving unit 110 Revolver developing unit 115 Bk developing unit 116 C developing unit 117 M developing unit 118 Y developing unit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H030 BB23 BB33 BB36 2H071 BA17 BA20 CA01 DA08 DA32 2H077 BA01 BA10 DA10 DA24 DB01 DB25 GA13

Claims (5)

[Claims] 1. An image forming apparatus comprising a revolver developing unit for integrally rotating and moving a plurality of developing units, wherein a T sensor provided for each of the plurality of developing units for detecting a toner concentration; Reading command means for reading a sensor output and supplying toner to the plurality of developing devices; optical communication transmitting / receiving means for transmitting a signal between the image forming apparatus main body and the reading command means by light; An image forming apparatus comprising: a power transfer unit that supplies power from a main body to at least the T sensor of the revolver developing unit, the read command unit, and the optical communication transmission / reception unit by a current transformer. 2. The optical communication transmitting / receiving means according to claim 1, wherein said optical communication transmitting / receiving means is opposed to said optical communication transmitting / receiving means on said image forming apparatus main body when said revolver developing unit is stopped at a developing position. Image forming device. 3. The image forming apparatus according to claim 1, wherein said communication transmitting / receiving means is located on a rotation axis of said revolver developing unit. 4. The image forming apparatus according to claim 1, wherein the power transfer unit faces the power transfer unit of the image forming apparatus when the revolver developing unit stops at the developing position. The image forming apparatus as described in the above. 5. The image forming apparatus according to claim 1, wherein said current transformer of said power transfer means is arranged in a ring shape around a rotation axis of said revolver developing unit.