JP2002221876A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tandem type image forming device with which a non- contact memory system mounted with nonvolatile memories on a plurality of exchange units and free from the contact reliability of a connector is inexpen sively realized. SOLUTION: A communication means provided in the image forming device has an amplification means provided for every signal control means to control a communication signal, a switch means to select one communication circuit among a plurality of communication circuits after amplifying the communication signal by the amplification means and an amplitude adjusting means to attenuate the amplitude of the communication signal passing through the switch means, thus communication with a plurality of nonvolatile memories is attained by switching the switch means.

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 such as an electrophotographic apparatus and an electrostatic recording apparatus having a consumable part such as a toner cartridge or a replacement part such as an apparatus for performing replacement depending on a service life.

[0002]

2. Description of the Related Art FIG. 9 is a block diagram showing a conventional tandem type image forming apparatus 500.

A tandem type image forming apparatus 500 is
It is composed of a plurality of image forming units of black (Bk), yellow (Y), magenta (M), and cyan (C).

In the above-mentioned image forming section, a photosensitive drum (image carrier) 18 is formed of an organic photosensitive member or an amorphous silicon photosensitive member. Is subjected to a uniform charging process.

[0005] Scanner units 11a, 11b, 11
c and 11d output laser light 13 modulated in accordance with an image signal of target image information from an image signal generating unit such as an image reading device (not shown), and output the laser light 13 through an optical lens system (not shown). The photosensitive drum 1 is moved by the illustrated deflection mirror.
By performing the scanning exposure on 8, an electrostatic latent image is formed on the photosensitive drum surface.

FIG. 10 is a diagram showing the configuration of the scanner unit 11a in the conventional image forming section 500.

The scanner unit 11a includes a semiconductor laser 31, a collimator lens 32, a cylindrical lens 33, a polygon mirror 34, and a scanner motor 3.
5, a spherical lens 36, an Fθ lens 37, a deflecting mirror 38, and a horizontal synchronization signal detector 39.

Next, the operation of the scanner unit 11a will be described.

A semiconductor laser 31 emits light in response to a laser drive signal modulated based on an image signal, and a laser beam is emitted from a collimator lens 32 and a cylindrical lens 3.
3 is shaped into a beam shape. The polygon mirror 34 is rotated by the scanner motor 35 that rotates steadily, and the laser beam reflected by the polygon mirror surface is scanned in a fan shape. Further, the laser beam is shaped by an optical lens group such as a spherical lens 36, an Fθ lens 37, and a deflecting mirror 38, and scans the photosensitive drum surface at a constant speed. The horizontal synchronization signal detector generally includes a photodiode and an amplifier, detects a laser beam to be scanned, and generates a synchronization signal in the main scanning direction.

The scanner units 11b, 11c,
The configuration and operation of 11d are the same as the configuration and operation of the scanner unit 11a.

The developing device 14 stores a developer (toner) therein, and generally has a toner conveying mechanism for charging and conveying the toner.

Photosensitive drum 18 on which electrostatic latent image is formed
The toner is selectively brought into contact with or in proximity to the developing roller 17 in accordance with the electrostatic state of the surface,
The adhesion of the toner visualizes the image.

The cassette 22 is a cassette for storing a transfer material 29. The transfer material fed from the cassette 22 by a paper feed roller is transferred to a photosensitive member in an image forming section by a transport belt 20 for holding and transporting the transfer material. It is transported between the drum 18 and the transfer device 19. At this time, the toner image on the photosensitive drum 18 developed in the development process is transferred to the transfer material 29 by the transfer device 19. By sequentially passing through the image forming units of four colors,
The color developer is multiply transferred. The residual toner on the photosensitive drum 18 that has not been transferred in the transfer process is removed and collected by the cleaning device 15 such as a cleaning blade.

The fixing device 23 is generally constituted by a plurality of opposed rollers, and has a heating section such as a heater inside or outside the rollers. Further, the fixing device 23 includes a temperature detector near the roller, and monitors the temperature with a CPU or the like.
By controlling the heating amount of the heater, the temperature is controlled so as to reach a predetermined temperature. The transfer material 29 to which the toner has been transferred in the transfer process is heated and pressurized by the fixing device 23 and is fused and fixed. Thereafter, the fixed transfer material 29 is conveyed through the paper discharge mechanism, discharged from the image forming apparatus, and printing is completed.

In such a conventional image forming apparatus 500, the developing device 14 for storing the toner is a replacement unit that needs to be replaced due to the consumption of the toner. Such an exchange unit detects the remaining amount of toner and the like,
The user is notified of the replacement time, and the user is replaced. It is more desirable for the user to detect the remaining amount of toner than to notify that the toner has run out, and to notify the user before the toner runs out and printing cannot be performed, so that the replacement unit can be prepared. .

Further, ideally, if the amount of consumables used is constantly reported, the user can accurately grasp not only the time of replacement but also the usage state of consumables. In this case, the information is used to determine whether the consumable is sufficiently new. As described above, it is desirable that the use state of the replacement unit can be accurately grasped.

However, replacement units such as consumables are
The image forming apparatus has a unit configuration different from that of the image forming apparatus. For example, when a developing device 14 used in another image forming device is mounted on another image forming device, it is determined how much the developing device 14 has been used. It is difficult to judge.

Therefore, a nonvolatile memory is mounted on the exchange unit, and information on the nonvolatile memory of the exchange unit is read even between different image forming apparatuses by cumulatively recording the usage of the exchange unit in the nonvolatile memory. Thus, the state of the replacement unit can be correctly grasped, and the user can be notified accurately.

In a conventional system, a technique is known in which a non-volatile memory such as an EEPROM is mounted on an exchange unit, and when the exchange unit is installed, it is connected to a main body of the image forming apparatus by a connector.

When a non-volatile memory is mounted on the replacement unit, a drawer connector with a fitting member that is easily inserted and removed when attaching and detaching is often used instead of a general harness connector at the connection portion. The fitting unit is formed with a replacement unit when the replacement unit is attached and detached, and a guide member that absorbs a position shift due to a tolerance of the main body device, and has a disadvantage that the cost is higher than that of a general harness connector.

Further, since the system equipped with the nonvolatile memory using the drawer connector is of a contact type, a contact failure may occur due to, for example, toner dust inside the main unit or dust entering from the outside. However, there is a drawback that there is a limitation that the contact must be constituted by a sliding contact which is self-cleaned when the connector is inserted and removed.

From such a viewpoint, there is a demand for a non-volatile memory system in which the main unit and the non-volatile memory of the exchange unit are not in contact with each other.

Therefore, in recent years, a memory system capable of non-contact communication using a nonvolatile memory such as FeRAM has been devised. This system is composed of a transmission circuit and a reception circuit. In general, the transmission circuit superimposes data on a carrier called a carrier, supplies power used in a nonvolatile memory to the carrier, and transmits and receives data. System. Each of the transmitting side and the memory unit side is configured to include an antenna. The transmission side antenna of the main unit is driven by the carrier, and the antenna of the memory unit on the exchange unit side facing in a non-contact manner is electromagnetically induced by electromagnetic waves to supply power to the memory unit. In this system, it is possible to avoid the disadvantage of the reliability of the connector contacts, which is a disadvantage of the contact type nonvolatile memory mounting system.

FIG. 11 is a circuit diagram showing a communication unit 600 in the conventional image forming apparatus 500.

The conventional communication means 600 is a circuit necessary for one-channel memory communication.

The communication IC 105 communicates with the memory unit 101 based on information specified by a CPU or a logic IC (not shown). In addition, the communication IC 105
A transmission signal is generated by superimposing an address, a command, and data of a memory unit designated by a CPU or a logic IC on a carrier for supplying power to a memory unit 101 having a built-in nonvolatile memory.

The transmission signal is amplified by the amplification circuit 104 into a transmission signal having an amplitude of several tens of volts, and the antenna unit 102 is driven via the coupling capacitor 110 to generate an electromagnetic wave. It supplies power and transmits superimposed data.

The inductor of the antenna unit constitutes a tuning capacitor 108 and a resonance circuit that uses a carrier wave of a signal as a resonance frequency. The memory unit returns a reception signal based on the transmission data. The received signal is transmitted to the antenna 10
2 is received by the receiving circuit 113 via the coupling capacitor 111.

Like the transmitting section, the inductor of the receiving section is
Together with the tuning capacitor 109, it constitutes a resonance circuit. From the received signal passing through the receiving circuit 113, the communication IC
105 retrieves the received data, which is read by a CPU or a logic IC (not shown). Such a system constitutes a conventional system that can read and write the nonvolatile memory of the exchange unit in a non-contact manner.

In this communication system of the non-contact memory, a communication IC is required. The disadvantage of this communication IC is that it is expensive because it is a communication IC dedicated to non-contact memory. Further, as described above, since this non-contact type memory communication system is constituted by the transmission circuit and the reception circuit, the number of parts of the electric circuit is large, and the transmission circuit,
If a common receiving circuit is used, it is necessary to communicate with a remote memory, and it is necessary to transmit a strong electromagnetic wave from an antenna.

On the other hand, the output by electromagnetic waves is regulated by the Radio Law of Japan, and it is not desirable to increase the output. Also, in order to prevent unnecessary radiation waves from being emitted, it is necessary to configure the transmission unit of the main unit and the non-volatile memory unit at a short distance and communicate with each other by weak electromagnetic waves.

[0032]

As described above, in the above conventional example, when a non-contact type non-volatile memory is mounted on a plurality of replacement units of a tandem type color image forming apparatus 500, a plurality of communication ICs are required. In addition, there is a problem that a plurality of transmission circuits and reception circuits are required, and a low-cost image forming apparatus cannot be provided.

Further, in the above conventional example, the transmission circuit,
When a plurality of sets of receiving circuits are formed, a communication circuit board becomes large, a space is required in the main body device, and there is a problem that implementation is difficult.

Further, in the above-mentioned conventional example, between a plurality of communication circuits and a plurality of transmission / reception circuits, there are variations in manufacturing of elements constituting the circuits and variations in patterns of substrates.
Since there is variation in output power, there is a problem in the Radio Law that it is necessary to suppress variation in the communication output of the transmission circuit in order to minimize unnecessary radiated radio waves.

According to the present invention, in a tandem image forming apparatus, a plurality of exchange units are provided with a nonvolatile memory,
It is an object of the present invention to provide an image forming apparatus that can realize a non-contact memory system irrelevant to the contact reliability of a connector at low cost.

[0036]

According to the present invention, there is provided an amplifying means provided for each signal control means for controlling a communication signal, and after the amplifying means amplifies the communication signal,
The communication unit provided in the image forming apparatus includes: a switch unit that selects one of the plurality of communication circuits; and an amplitude adjustment unit that attenuates an amplitude of a communication signal transmitted through the switch unit. By communicating with the plurality of nonvolatile memories by switching the switch means.

[0037]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] In the following embodiments, since there are a plurality of units having the same function, a, b, c and d are given to the designation numbers. In addition,
The printing operation and the like of the image forming apparatus are the same as those in the above-described conventional example, and thus detailed description thereof is omitted.

FIG. 1 is a view showing an image forming apparatus 100 according to a first embodiment of the present invention.

In the image forming apparatus 100 of the first embodiment, the developing device 14 described in the prior art
7 together with one unit. The developing device 14 is a replacement unit, and is a unit that is replaced when the toner inside the developing device 14 is consumed. A memory unit 101 is mounted on a front upper surface of this unit. The main body of the image forming apparatus 100 includes a communication unit 200, and an antenna unit 102 is disposed at a position facing the memory unit 101. The antenna unit 102 allows the main body of the image forming apparatus 100 to obtain information on the developing device 14 (for example, information on toner consumption or remaining amount).

FIG. 2 is a diagram showing a communication unit 200 in the image forming apparatus 100 according to the first embodiment of the present invention.

The communication unit 200 includes a communication IC 105 and memory units 101a and 101 each having a built-in nonvolatile memory attached to the developing unit 14 as an exchange unit.
b, 101c, 101d, and antenna units 102a, 102b, 10
2c, 102d, an amplifier circuit 104 capable of adjusting the gain in the transmission circuit, and an amplitude adjustment circuit 11 in the transmission circuit
2a, 112b, 112c, and 112d, an analog switch 106 for switching a transmission signal, an analog switch 107 for switching a reception signal, and a reception circuit 113 are provided.

The communication IC 105 communicates with the memory unit 101 based on information specified by a CPU or a logic IC (not shown), and the CPU or the logic IC supplies a carrier for supplying power to the memory unit 101. A transmission signal is generated by superimposing the address, command, and data of the specified memory unit.

After the transmission signal is amplified by the amplifier circuit 104 into a transmission signal having an amplitude of several tens of volts, the signal is switched to each channel by the analog switch 106.
Here, the analog switch 106 is constituted by an FET, and is a multiplexer type general-purpose I / O having a built-in decoder function.
C is used.

The SELECT0 and SELECT1 signals are
Each of these signals is a signal for selecting one of the four memory units. The signal is specified by a CPU or a logic IC (not shown), and the analog switch corresponding to the memory unit to be selected is turned on by a decoder built in the analog switch.

The above-mentioned analog switch can be constituted by a normal analog switch other than the multiplexer type.
It is a switch using a diode bridge, a switch using one discrete FET, or an analog switch combining N-type and P-type FETs, and may be a mechanical relay or the like. Also, the decoder
The same function can be realized by configuring the device externally.

Next, the amplification circuit 10 in the communication section 200
4 will be described.

FIG. 3 is a circuit diagram showing an amplifier circuit 104 in the image forming apparatus 100 according to the first embodiment of the present invention.

The input signal is coupled to the base of a transistor 133 which is coupled by a capacitor 132 and DC biased by resistors 114, 115 and 116. This transistor is desirably for high frequency amplification, which has excellent frequency characteristics. The transistor drives the inductor 119 connected to the collector by the input signal and amplifies the signal to a large amplitude. The resistance 120 is D
Determine the C bias current, the capacitor 117 and the resistor 118
Determines the AC gain.

The signal thus amplified is cut through the coupling capacitor 121 of the output stage, where the DC component is cut off, and is output as an AC component amplitude signal.

According to the image forming apparatus 100 of the first embodiment, the transmission amplitude can be changed by changing the resistance value of the resistor 118 of the transmission section. That is, the output can be adjusted. As described above, since the transmission circuit can be adjusted, it is possible to obtain an output amplitude of the antenna sufficient to communicate with the memory unit even if the components of the transmission circuit vary.

Returning to the communication section 200 shown in FIG. The signal passed through the switch 106 is output to the amplitude adjustment circuit 11
2 limits the amplitude.

FIG. 4 is a diagram showing the amplitude adjustment circuit 112a in the image forming apparatus 100 according to the first embodiment.

The signal is obtained by dividing the resistance of the variable resistor 122 (resistance value rv) and the fixed resistor 123 (resistance value r1).
The amplitude is reduced to r1 / (r1 + rv), and the signal whose amplitude is reduced is sent to the next stage. Normally, the variable resistor 122
Is set to 0 ohm, and the input signal is passed as it is. If the signal amplitude at the antenna is too large and the radio waves are too strong for the operating conditions of the Radio Law or non-contact memory, rv is increased to reduce the amplitude. Amplitude adjustment circuit 112
Is provided for each channel so that adjustment of all channels is possible.

The amplitude adjustment circuits 112b, 112c,
The configuration of 112d is the same as the configuration of the amplitude adjustment circuit 112a.

The transmission signal whose amplitude is adjusted drives an antenna unit 102 composed of an inductor via a coupling capacitor 110 to generate electromagnetic waves, thereby supplying power to the memory unit 101 and The superimposed data is transmitted.

The inductor of the antenna unit and each of the tuning capacitors 108a, 108b, 108c, 108d constitute a resonance circuit having a signal carrier as a resonance frequency. The memory unit returns a reception signal based on the transmission data. The received signal is received by the antenna unit 102 and received by the receiving circuit via the analog switch 107. The inductor of the receiving unit as well as the transmitting unit, together with the tuning capacitors 109a, 109b, 109c, and 109d, form a resonance circuit.

FIG. 5 is a diagram showing the receiving circuit 113 in the image forming apparatus 100 according to the first embodiment.

The received signal is supplied to the resistor 124 and the diode 12
The received signal is rectified by a half-wave rectifier circuit composed of a capacitor 9 and a capacitor 125, and the level of the rectified signal is compared and detected by a comparator 128. The reference voltage for comparison is
The power supply voltage is obtained by dividing the resistances of the resistors 126 and 127. The communication IC 105 extracts the received data from the received signal, and a CPU or a logic IC (not shown) can read the data. Such a system constitutes a system that can read and write the nonvolatile memory of the exchange unit in a non-contact manner.

Next, an algorithm at the time of adjustment in the first embodiment will be described.

First, parameters indirectly indicating the power, such as the power of all antennas or the voltage amplitude at the antenna, are measured. Between the plurality of channels, there is a variation in output power due to a variation in manufacturing elements constituting a circuit and a variation in a pattern of a substrate. The variable resistor 118 of the amplification stage is changed and the gain is adjusted so that the output of the channel having the weakest output among them has a predetermined margin with respect to the lower limit at which communication with the non-contact memory is possible.

Next, if there is a channel whose output exceeds the regulation value of the Radio Law or the operating condition of the non-contact memory, the variable resistor 12 of the amplitude adjusting circuit 112
2 and attenuate so as to fall within the regulation value. This adjustment is performed for all channels exceeding the regulation value. If there is no channel exceeding the regulation value, adjustment by the amplitude adjustment circuit is not required.

As described above, one communication IC has one
By providing two amplification stages, and providing the switches 106 and 107 and the amplitude adjustment circuits 112a, 112b, 112c and 112d, it becomes possible to communicate with the non-contact memories of a plurality of exchange units, thereby reducing the cost of parts and the board area. As a result, it is possible to realize an image forming apparatus including a low-cost and highly reliable non-contact memory system. In addition, even if there is a variation in output power due to a variation in manufacturing of elements constituting a circuit or a variation in a pattern of a substrate, the amplitude adjustment circuits 112a to 112d (output adjustment circuits) are provided for each channel, thereby exceeding the standard. The signal amplitude of the high power channel can be adjusted to meet the standard.

Although the above embodiment uses the non-contact memory attached to the four toner containers of yellow, magenta, cyan, and black, the non-contact memory may be attached to a replacement part other than the toner container. Further, a number other than 4 may be set as the number of non-contact memories.

Further, the first embodiment has one communication IC and one amplifier circuit, but if one communication IC communicates with a plurality of memory units, the cost can be reduced. When communicating with a memory unit group at a largely different position, a plurality of communication ICs are provided, and
Communication with a plurality of nearby memory units may be performed.

[Second Embodiment] FIG. 6 is a diagram showing a circuit configuration of a communication unit 300 in an image forming apparatus according to a second embodiment of the present invention.

The image forming apparatus according to the second embodiment has the same shape and configuration as the image forming apparatus 100.

In the first embodiment, at least two resistors are provided for each memory unit. Therefore, there is a concern that the cost is increased. In this regard, in the second embodiment, the tuning capacitor of the antenna unit is a variable capacitor, and thereby the amplitude is adjusted.

The second embodiment shown in FIG. 6 is the same as the first embodiment shown in FIG.
In this embodiment, variable capacitors 130a to 130d are provided in place of the capacitor 108, in which 2a to 112d are omitted.

When the value of the inductor of the antenna is 11 and the capacitance of the tuning capacitor is c1, the tuning circuit is 1 /
Resonates at a frequency of 2π√ (l1 · c1). Usually, the resonance frequency is set to the frequency of the carrier.

In the first embodiment, the capacitance of the tuning capacitor of the channel whose amplitude is to be suppressed is changed, and the resonance frequency is slightly shifted, so that the gain of the tuning circuit at the frequency of the carrier is reduced, and the amplitude is adjusted.

Next, an adjustment algorithm in the second embodiment will be described.

First, the power of all the antennas or a parameter indirectly indicating the power, such as the voltage amplitude at the antenna, is measured. Between the plurality of channels, there is a variation in output power due to a variation in the manufacture of the elements constituting the circuit and a variation in the pattern of the substrate. In order that the output of the channel with the weakest output among them has a predetermined margin with respect to the lower limit that can communicate with the non-contact memory,
The gain is adjusted by changing the variable resistor 118 of the amplification stage.

Next, if there is a channel whose output exceeds the regulation value of the Radio Law or the operating condition of the non-contact memory, the value of the capacitor of the tuning circuit is changed to attenuate the signal, and the regulation value is reduced. Adjust to fit within. This adjustment is performed for all channels exceeding the regulation value. If there is no channel exceeding the regulation value, adjustment by the amplitude adjustment circuit is not necessary.

As described above, one communication IC corresponds to one communication IC.
Providing two amplification stages and providing switches and variable capacitors enables communication with non-contact memories of multiple replacement units, and low cost and high reliability by reducing board costs by reducing component costs and board area. An image forming apparatus provided with a non-contact memory system having a characteristic can be realized.

Furthermore, even if there is a variation in output power due to a variation in the manufacture of the elements constituting the circuit or a variation in the pattern of the substrate, the output can be adjusted by providing a variable capacitance in each channel, so that the output is larger than the standard. The signal amplitude of the power channel can be adjusted to meet the standard.

Although the above embodiment has the non-contact memory attached to the four toner containers of yellow, magenta, cyan and black, the non-contact memory may be attached to a replacement part other than the toner container. Further, the number of non-contact memories does not necessarily need to be four. Further, in the second embodiment, there is one communication IC and one amplifier circuit. However, if communication is performed with a plurality of memory units using one communication IC, the cost can be reduced. When communicating with a group, a plurality of communication ICs may be provided and each may communicate with a plurality of nearby memory units.

[Third Embodiment] FIG. 7 is a diagram showing a circuit configuration of a communication section 400 in an image forming apparatus according to a third embodiment of the present invention.

The image forming apparatus according to the third embodiment has the same shape and configuration as the image forming apparatus 100.

The third embodiment differs from the first embodiment shown in FIG. 2 in that an automatic amplitude adjusting circuit 131 is provided between a channel switching switch and an antenna. In the first and second embodiments, the voltage amplitude of the antenna is measured for each channel, the overall gain is adjusted by the resistor 118, and whether or not the individual adjustment is performed by the amplitude adjustment circuit 112 is determined. It is necessary to perform the actual adjustment manually, and there is a problem that adjustment time and cost are required.

Therefore, in the third embodiment, the automatic amplitude adjusting circuits 131a, 131b, 131c and 131d are provided so that the output amplitudes of all the channels become substantially constant.

FIG. 8 is a diagram showing the automatic amplitude adjustment circuit 131a in the communication section 400.

The automatic amplitude adjusting circuits 131b and 131
The configurations of c and 131d are the same as the configuration of the automatic amplitude adjustment circuit 131a.

In 1 is a transmission signal input, and out is
Is the output. In2 is an input for monitoring the output voltage of the antenna.

Vref is a reference voltage corresponding to the target value of the amplitude, and is a voltage value corresponding to the amplitude that can sufficiently communicate with the memory unit and does not exceed the operating conditions of the Radio Law or the non-contact memory. Is set. The voltage of the antenna is input to the peak detection circuit 141, and the peak value is input to the inverting terminal of the comparator 138.

When the amplitude of the output voltage of the antenna is too large than the target value, the output of the peak detection circuit 141 becomes larger than the reference voltage Vref, and the output of the comparator decreases. Therefore, the gate voltage of the NMOS 139 decreases, and the ON resistance increases. The input signal is divided and output by the on-resistance of the NMOS 139 and the resistance 140, so that the voltage of the out terminal decreases. Therefore,
Negative feedback is applied so that the output voltage of the antenna decreases.

On the other hand, when the amplitude of the output voltage of the antenna is too smaller than the target value, the output of the peak detection circuit 141 becomes
The voltage becomes lower than the reference voltage Vref, and the output of the comparator increases. Therefore, the gate voltage of the NMOS 139 increases, the ON resistance decreases, and the voltage of the out terminal increases. Therefore, negative feedback is applied so that the output voltage of the antenna increases.

As described above, the output of the antenna is V
Since the amplitude is automatically adjusted so as to be a target amplitude corresponding to ref, the magnitude of the amplitude is determined for each channel, and the need for manual adjustment as needed can be omitted, so that the adjustment cost can be reduced.

The gain of the amplifying circuit is set so that the output of the channel having the weakest output has a sufficient margin with respect to the lower limit at which communication with the non-contact memory is possible.
The middle resistor 118 is selected. The adjustment of the amplitude
Since the automatic amplitude adjustment circuit performs the operation, the amplification circuit only needs to output a sufficiently large signal, and the resistance value does not necessarily need to be variable.

Here, the operation of the peak detection circuit 141 in the automatic amplitude adjustment circuit 131a will be briefly described.

The output is higher than the initial output V0 of the operational amplifier 137 by i
When the input voltage of n2 is small, the output of the operational amplifier 132 decreases. The non-inverting input of the operational amplifier 137 is initially V
Since it is 0, the diode 134 is reverse biased,
The voltage of the non-inverting input of the operational amplifier 137 is maintained at V0. Therefore, the output of the operational amplifier 137 forming the voltage follower remains unchanged at V0.

Conversely, when the input voltage of in2 is higher than V0, the output of the operational amplifier 132 increases. Since the non-inverting input of the operational amplifier 137 is initially at V0, the diode 134 becomes forward biased, the voltage of the non-inverting input of the operational amplifier 137 increases, and the output of the operational amplifier 137 forming a voltage follower also increases. As described above, the circuit 131 functions as a peak detection circuit.

Here, the resistor 133 is connected to the diode 134
And a capacitor 136 is a hold capacitor. Resistance 1
Reference numeral 35 denotes a discharge resistor for returning the peak hold circuit to the initial state when the carrier stops.
The time constant of the RC circuit constituted by 5 and the capacitor 136 is selected to be sufficiently large with respect to the period of the carrier.

The other communication configurations are the same as those described in the first embodiment.

The system as described above can read / write the nonvolatile memory of the exchange unit in a non-contact manner, is realized at lower cost, and can omit the man-hour for adjustment. Furthermore, even if there is a variation in the output power due to a variation in the manufacturing of the elements constituting the circuit or a variation in the pattern of the substrate, in each channel, the signal amplitude of the channel having a power larger than the standard is adjusted by the automatic output adjustment circuit, It can fit into the standard.

In the third embodiment, yellow,
Although the non-contact memory is provided for the four toner containers of magenta, cyan, and black, the non-contact memory may be provided for replacement parts other than the toner container. Furthermore, the number of contactless memories does not necessarily need to be four. Further, in the above embodiment, there is one communication IC and one amplifier circuit. However, if communication is performed with a plurality of memory units using one communication IC, the cost can be reduced. When communication is performed with a memory unit group, a plurality of communication ICs may be provided, and each may communicate with a plurality of memory units in the vicinity.

That is, the communication unit 200 according to the first embodiment.
Thus, a non-contact memory is mounted on a plurality of exchange units, and a tandem image forming apparatus using a non-contact memory system irrelevant to the contact reliability of the connector can be realized at low cost. Specifically, a switch (switch for switching a channel) for providing one amplification circuit with a variable amplification factor for the output of one communication IC and switching the amplified signal to one of a plurality of memory units;
With a circuit that can adjust the amplitude of the amplified signal, after adjusting the gain of the amplification stage so that the power of the channel with the smallest output among the output variations existing between the channels can communicate with the non-contact memory, If there is a channel with a large output exceeding the standard of the Radio Law or exceeding the upper limit of the power supply voltage created by the non-contact memory, the amplitude is adjusted by the amplitude adjustment circuit.
One memory control IC and one amplifier circuit communicate with a plurality of non-contact memories.

Here, the amplifying circuit acts to amplify the output of the memory control IC so that the power of the channel with the smallest output is sufficient to communicate with the non-contact memory. The switch operates to select one of the outputs of one amplifier circuit from a plurality of channels. The amplitude adjusting circuit adjusts the signal amplitude of a channel having a power larger than the standard and acts so as to be within the standard.

In the communication section 300 according to the second embodiment, one communication IC is provided with one amplification circuit having a variable amplification factor, and a switch for switching the amplified signal and transmitting the signal to the non-contact memory. And an antenna section composed of an inductor. After adjusting the gain of the amplification stage so that the power of the channel with the smallest output among the output variations existing between the channels can communicate with the non-contact memory, it exceeds the standard of the Radio Law or the power supply made with the non-contact memory If there is a channel with a large output exceeding the upper limit of the voltage, one memory control I / O can be performed while complying with the regulation by adjusting the value of the variable capacitor of the tuning circuit of the antenna unit and attenuating the amplitude.
C. Communication of a plurality of contactless memories is performed by one amplifier circuit.

Here, the amplifying circuit acts to amplify the output of the memory control IC so that the power of the channel with the smallest output becomes sufficient to communicate with the non-contact memory. The switch operates to select the output of one amplifier circuit from one of a plurality of channels. The variable capacitance acts to attenuate the signal amplitude of a channel having a power larger than the standard and to keep the signal amplitude within the standard.

In the communication section 400 according to the third embodiment, one amplification circuit with a variable amplification factor is provided for one communication IC, and a switch for switching the amplified signal and a signal for controlling the amplitude of the amplified signal are provided. A circuit that can be automatically adjusted is provided.

Here, the amplifier circuit acts to amplify the output of the memory control IC so that the power of the channel with the smallest output becomes sufficient to communicate with the non-contact memory. The switch operates to select the output of one amplifier circuit from one of a plurality of channels. The automatic amplitude adjustment circuit automatically adjusts the output amplitude of the antenna so that the output amplitude of each channel does not exceed the standards of the Radio Law or exceed the upper limit of the power supply voltage created by non-contact memory. Therefore, the labor for adjusting the output amplitude can be omitted.

[0102]

According to the present invention, in a tandem type image forming apparatus, a nonvolatile memory is mounted on a plurality of exchange units, and a non-contact memory system irrelevant to the contact reliability of a connector can be realized at low cost. It has the effect of being able to.

A communication IC which is a disadvantage of the non-contact method
Therefore, low cost can be realized because the transmission and reception circuits are partially shared, so that space saving and low cost can be realized. By performing a plurality of nonvolatile memory communications with one communication IC, if the number of exchange units is four, the communication IC cost can be reduced to a quarter.
Simplification and cost reduction of peripheral circuits such as an amplifier circuit can be realized.

Further, according to the present invention, by providing an amplitude adjusting circuit for each channel, it is possible to adjust each of a plurality of transmission outputs to a necessary and sufficient output. This method has an effect that an effective image forming apparatus can be designed with respect to compliance with the Radio Law and suppression of unnecessary radiation radio waves.

According to the present invention, it is possible to improve the usability by mounting a nonvolatile memory in a plurality of exchange units, and it is possible to achieve a low-cost and highly reliable system.

[Brief description of the drawings]

FIG. 1 is an image forming apparatus 10 according to a first embodiment of the present invention.
FIG.

FIG. 2 is an image forming apparatus 10 according to a first embodiment of the present invention.
FIG. 5 is a diagram showing the communication unit 200 at 0.

FIG. 3 is an image forming apparatus 10 according to a first embodiment of the present invention.
FIG. 3 is a circuit diagram showing the amplifier circuit 104 at 0.

FIG. 4 is a diagram illustrating an amplitude adjustment circuit 112a in the image forming apparatus 100 according to the first embodiment.

FIG. 5 is a diagram illustrating a receiving circuit in the image forming apparatus according to the first embodiment;

FIG. 6 is a diagram illustrating a circuit configuration of a communication unit 300 in an image forming apparatus according to a second embodiment of the present invention.

FIG. 7 is a diagram illustrating a circuit configuration of a communication unit 400 in an image forming apparatus according to a third embodiment of the present invention.

8 shows an automatic amplitude adjustment circuit 131 in the communication section 400. FIG.
FIG.

FIG. 9 is a configuration diagram showing a conventional tandem type image forming apparatus 500.

FIG. 10 is a diagram illustrating a configuration of a scanner unit 11a in a conventional image forming unit 500.

FIG. 11 shows a communication unit 6 in a conventional image forming apparatus 500.
It is a circuit diagram which shows 00.

[Explanation of symbols]

 Reference numeral 100: an image forming apparatus according to the first embodiment; 101, a memory unit; 104, an amplifying circuit; 106, 107; a switch circuit; 112a to 112d; an amplitude adjusting circuit; 131a to 131d: automatic amplitude adjustment circuit; 200, 300, 400: communication unit.

Claims (5)

[Claims] An exposure system having a light-emitting element and a light-emitting element driving unit, wherein the exposure system is exposed to light energy of the light-emitting element;
An image carrier for forming an electrostatic latent image is provided, and a target electrostatic latent image is formed on the image carrier by controlling the exposure system based on print data. An image forming section for selectively attaching a developer to an image forming section, and a plurality of transfer sections for transferring the developer image to a transfer material are respectively provided, and images are formed simultaneously or sequentially to form a plurality of images. After the image is transferred to the transfer material, a fixing unit for fixing the developer to the transfer material by heating or pressurizing is provided. A communication means for performing non-contact communication by electromagnetic waves, and an amplifying means provided for each signal control means for controlling a communication signal in the image forming apparatus for communicating with the plurality of nonvolatile memories. Switching means for selecting one of the plurality of communication circuits after the amplification means amplifies the communication signal; and amplitude adjusting means for attenuating the amplitude of the communication signal passing through the switching means. Wherein the communication means has a function of communicating with a plurality of nonvolatile memories by switching the switch means. 2. The image forming apparatus according to claim 1, wherein the amplitude adjusting unit is a unit including at least one resistor and at least one variable resistor. 3. The image forming apparatus according to claim 1, wherein the amplitude adjusting unit is a unit configured by a variable capacitor connected in parallel with an inductor forming an antenna. 4. An exposure system having a light-emitting element and a light-emitting element driving unit, wherein the exposure system is exposed by light energy of the light-emitting element,
An image carrier for forming an electrostatic latent image; forming an intended electrostatic latent image on the image carrier by controlling the exposure system based on print data; An image forming section for selectively attaching a developer to an image forming section, and a plurality of transfer sections for transferring the developer image to a transfer material are respectively provided, and images are formed simultaneously or sequentially to form a plurality of images. After the image is transferred to the transfer material, a fixing unit for fixing the developer to the transfer material by heating or pressurizing is provided. A communication means for performing non-contact communication by electromagnetic waves, and an amplifying means provided for each signal control means for controlling a communication signal in the image forming apparatus for communicating with the plurality of nonvolatile memories. Switch means for selecting one of the plurality of communication circuits after the amplification means amplifies the communication signal; and automatically adjusting the amplitude of the communication signal via the switch means to a predetermined value. And an automatic amplitude adjusting means for adjusting the amplitude of the image data. The image forming apparatus communicates with a plurality of nonvolatile memories by switching the switch means. 5. The automatic amplitude adjusting means according to claim 4, wherein the automatic amplitude adjusting means comprises: a peak detection circuit for detecting a peak level of a transmission signal; a comparator for comparing an output voltage of the peak detection circuit with a reference voltage; An image forming apparatus, comprising: an attenuation circuit that changes an attenuation rate based on an output voltage.