JPS58129445A - Copying device - Google Patents

Abstract

PURPOSE:To simplify control of an exposure lamp and to remarkably reduce its effect on a photoreceptor, by controlling bias voltage for developing process using a one component developer, when necessary, to adjust density of an original. CONSTITUTION:A blade 67 having AC bias voltage applied from a power supply circuit 68 for bias voltage slides in contact with the nondeveloping part of a sleeve 64. Developing bias voltage VDEV applied to this sleeve is changed to give a result similar to the case of changing intensity of an exposure lamp. Since original density can be adjusted with the developing device, the exposure lamp needs only on-off control, but not any variable power control, thus permitting control of the lamp to be very simplified, developing conditions to be improved by applying AC bias voltage to the sleeve 64, and uneven development, especially, in low density to be suppressed to a low degree.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a photographing apparatus that once has a vertical function on an original and performs 'kAgI processing using a -component developer.

[Technical Landscape of the Invention and Points of Interest] Generally known RCM electronic copying machines perform all development processing using a two-component developer consisting of toner and carrier. Recently, a -component developer, that is, one that performs fA image processing using a one-component resistive magnetic toner, has been developed and is being put into practical use.

Such an electronic copying apparatus usually has an original bucket density y4 adjustment function. The specific means for this TJp density adjustment function is to variably control the power supplied to the exposure rung according to the density of the original, and to control the light amount of the exposure rung and change it to exposure 1. . However, in such conventional document density adjustment means, the document a degree adjustment is controlled on the exposure rung side, and therefore has the disadvantage that the control of the exposure rung becomes very complicated. Moreover, since the power supplied to the exposure rung is variably controlled, the light source spectral distribution (color part [) of the rung] changes by varying the power of the exposure lamp, and this causes changes in the sensitivity of the photoreceptor drum, etc. Another disadvantage is that the influence on the drum is greatly increased.

[Object of the Invention] The present invention was developed in view of the above circumstances, and its purpose is to greatly simplify the control of the Arashiko rung,
Moreover, it is possible to provide a photographing apparatus that can significantly reduce the shadow 4 on the photoreceptor due to one-time adjustment of the document.

[Praise of the Invention] The present invention is based on a subject device in which a one-component boundary image is generated in the current GLF process, and a bias voltage to the developing unit in the boundary image process is required to be applied to the camera. (2) A bias voltage control means is provided, and the control means performs stitching to the original density by Q-quality control of the developing bias voltage. In other words, once the original B11
This is to control the excess on the developer side.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an electronic copying apparatus according to the present invention.

In the figure, reference numeral 1 denotes a main body of the copying apparatus, and an original material 82 is provided on the upper part of the main body 1 so as to be movable in the direction of arrow a. Although not shown, the document table 2 is provided with a paper presser cover. When the document table 2 moves forward, the document is illuminated by the exposure run f3 provided at a predetermined position below, and the reflected light is guided onto the photoreceptor drum 5 via the convergent light transmitter 4. 1 of the manuscript. [1i
The i image is formed (exposed) on the surface of the photoreceptor drum 5. The photosensitive drum 5 rotates in the direction of the arrow, and first the charger 6
The surface of the original is charged, and then the image of the original is exposed to light to form an electrostatic latent image.
A one-component anti-resistive toner is applied to the toner to form a visible image, and the toner passes through a static eliminator 8 for neutralizing the toner.

On the other hand, the paper P is transferred from the paper feed cassette 11 to the paper feed roller 12.
It is taken out by the aligning roller 14 through the guide path 13f.
The toner is sent to the transfer section, where it comes into contact with the photoreceptor drum 5, and the toner particles on the photoreceptor drum 5 are transferred by the action of the transfer charger 150. The paper P after the transfer is peeled off from the photosensitive drum 50 by the action of the peeling charger 16,
The sheet is guided by a conveyance path 17 to a heat roller 18 serving as a constant 7ilr device, where the transferred image is layered, and then discharged to a sheet discharge tray 20 by a sheet discharge roller 19. After the photosensitive drum 5 has been transferred, the charge is removed by a wL eliminator 21, and then residual toner on the surface is removed by a cleaning device jt22.
Finally, the static electricity elimination rung 23 erases the static image and returns to the initial state.

In addition, 24 is a manual feed guide body that feeds the paper with the left hand.
5 is the M! supplied from this manual feed body 2-! cil
- The feeding roller 26 is a guide path that guides the paper fed into the bag by the feeding roller 25 to the aligning roller 14. Further, 27 is a scraping fan for cooling the heat roller 18, etc., 28 is a motor for moving the original platen 2 and rotating the photosensitive drum 5, and 29 is a motor for controlling the reciprocating movement of the original platen 2. It is a magnetic clutch.

FIG. 2 shows the document table 2 and its driving mechanism in detail. That is, the document table 2 is made of reinforced transparent glass, and its -9111 edge (backward 141 in the drawing)
I) is slidably fitted into a slide rail 32 formed by bending the upper part of one frame 31 into a U-shape. 11. In addition, the other side edge of the document table 2 (Drawing 1
5il side 9111) is supported via the support rail 35, kite rail 36 and support members 37 and 37' provided on the upper fold s34 of the other rail 33. That is, the support rail 35 is connected to the frame 3.
It is a U-shaped member fixed on the bent part 34 of No. 3, and has a sliding smooth member 38 in its recess, and an inverted U-shaped kite rail 36 is slidably fitted above it. It matches. A U-shaped support member 37.3' is fitted into 1111s of the guide rail 36, and the side edge of the document table 2 is fitted into the recess of this support member 37.3'/. Further, a document table drive mechanism 39 is provided on the frame 33 side. This drive mechanism 39 includes the motor 28 and the motor 28.
The rotation of the electromagnetic clutch 29 is transmitted through the timing bell L, the Gooley-O is fixed to the rotating shaft of the electromagnetic clutch 290 and is located on the front side of the frame 33, and the document table is located on the front side of the frame 33. The googly (1) provided near the bottom of 2 is wound once around these googly 40, 41, one end is fixed to the support member 37 on the right side in the figure, and the other end is connected to the - on the left side in the figure via a coil spring 42. The drive wire 43 is fixed to the IS member 37, and the rotation of the motor 28 is transmitted to the forward or backward electromagnetic clutch 29 to move the document table 2 in the direction of the arrow 1 (horizontal direction in the figure). It is becoming more and more voluntary.

Next, with reference to FIGS. 2 and 3, the detection mechanism for detecting the entire movement position f of the document table 2 will be explained. As shown in FIG. 2, a magnet 4 is provided at a predetermined position on the back surface of the document table 2 [(a position to the right of the middle position txt in the figure), and a magnet 4 is provided at the top of the main body 1 on the surface of the document table 20. Nearby, three reed switches 45, 4 are installed at regular intervals.
6t-7 are provided, and these constitute a position detector. In addition, the above-mentioned reed switch 45.46.
Each of the output signals 47 is sent to a control system, which will be described later, and is used as an open side j signal for the document table driving mechanism 39 or the paper feeding mechanism for paper P, etc. Here, to explain an example of the positional relationship between the magnet 44 and the reed switches 45, 46, 47, the magnet 4 and each reed switch 45, 46, 17 are arranged on the same line.
For example, as shown in Figure 83, the distance L1 between the reed switches 5 and 47 at both ends is the maximum size (
For example, the distance between the reed switch 44 at the right end and the reed switch 46 at the middle is slightly longer than the same length in the longitudinal direction of a document of the minimum size (for example, B5 size) (for example, A3 or B4 size). The main body I and the document table 2 should be further extended to the extent that the length of the original is longer than the length of the original.
The magnet and toe 4 are set to maintain a distance Ls t- which is slightly offset to the right from the position of the reed switch 46 at the position where the reed switch 46 and the reed switch 46 coincide (stop position).

The reed switch 45 at the right end is a movement start position detection switch (hereinafter referred to as table start switch).
The intermediate road switch 46 is used as a stop position output switch (hereinafter referred to as a table home switch), and the left end reed switch 47 is used as a travel limit position detection switch (hereinafter referred to as a table limit switch). Arrangements that achieve such objectives 1
are in a relationship. Although not shown, a vapor start switch (hereinafter referred to as vapor start switch) is provided at a predetermined location between the switches 45 and 46.

FIG. 4 shows the developing device 7 using a one-component high-resistance toner.
Include something that shows the composition of. In the figure, 51 is a main body frame, which includes a first casing 52 and a second cage/group 5.
3 are arranged facing each other, and side frames sa and s5 (only the frame 54 is shown) ft are provided at both longitudinal ends of the casings 52 and 53, respectively, and are integrally constructed.
A toner supply opening 56 for supplying toner is formed in the upper part of the image forming apparatus 7, and a developing opening 57 is formed in the lower left side. A toner storage section 58, a developing roller storage section 59, a temporary toner storage section 60, and a toner receiving section 61 are formed inside the main body frame 51 configured as described above. Note that the first casing 5
A doctor grade 62 is integrally formed at the corner portion of 2. This doctor grade 62 is fA1 which will be described later.
#1tt- of m-type toner conveyed by roller 63
This is for uniformity. Further, a developing roller 63 is housed in the 3Jl image roller housing section 59. The developing roller 63 is a cylindrical rotating body made of a non-magnetic material such as aluminum or stainless steel.
(hereinafter referred to as a sleeve) 64, and a magnet roller 65 provided within this sleeve 64. Both the sleeve 64 and the magnet roller 65 are rotatable to the side frames 54 and 55 via mail bearings (not shown). It is supported by a pivot stone and can be rotated freely.

Next, the method of applying a bias voltage to the imager 7 constructed as described above, the conveyance of magnetic toner, etc. will be explained with reference to FIG. As shown in the figure, the magnet roller 65 has N and S poles arranged at equal intervals so that each pole has a super-number of poles 9, thereby creating vertical lines of magnetic force on the outer circumferential surface of the sleeve 6-. is starting to form. The sleeve 64 of the developing roller 63 rotates in the direction of arrow C with respect to the photosensitive drum 5 rotating in the direction of arrow A, and the magnet roller 65 rotates in the direction of arrow d in the opposite direction. A part of the developing opening 67 formed in the main body frame 51 is exposed, and a fixed pinion gear G1 is formed between the photosensitive drum 5 and the outer peripheral surface of the sleeve 64. It turns out. As a result, the magnetic toner stored in the toner storage section 58 receives the magnetic force of the magnet roller 65, so that the magnetic toner is
It is sucked in the form of a soft brush that stands upright on the outer granite surface.
The attracted magnetic toner 66 is conveyed in the direction of arrow C as the IJ-f6a rotates. Then, this magnetic toner 66 is transferred to the photosensitive drum 5 via the gear lug G.
The person is attracted to the silent W latent image formed on the winding of the wind and is forced to stop.

In this embodiment, the gear between the tip of the doctor blade 62 and the sleeve 64, f G ! is about 0.35n V
Gear between C1 photosensitive drum 5 and sleeve 64, fG1
is about 0.40 II lfM K K, and the thickness Dt of the magnetic toner 66 at the pole position after being made uniform by the doctor grade 62 is set to about 50 to 0.55 mm. Therefore, photoreceptor drum 5 and three f6g
Gear with.

At the position G1, the magnetic toner 66 is in slight contact with the surface of the photoreceptor drum 5. Further, in FIG. 5, a power supply blade 67 is in sliding contact with the non-developing portion of the sleeve 64, and an AC bias voltage (approximately 800 Hz) from a development bias power supply circuit 68 is applied to this blade 67. Note that the parts other than the developing roller 63, that is, the parts of the casing 52 and 53, are attached to the main body frame 51.
and is electrically insulated from the developing roller 63.

FIG. 6 shows an operation panel, which is provided on the front upper side of the main body 1. In the figure, 71 is a panel main body, and this main body 71 includes a print key 72, a clear key 72 for correcting setting data or performing a straggle operation.
Strike! Key 73, numeric keypad 74 for setting the number of copies, etc., number display to display the set number of copies or number of copies, sliding variable resistor @76 for 8411 degree adjustment, operating status display section 78, green onion ready (READY) A display rung 79 and a (WAIT) display rung 80 are provided. The above status display s7B includes a paper jam display rung 181, a cleaner cleaning display rung 7Jjx, a)ner supply display rung 78s1, and a paper supply display rank 78.
It consists of 4 etc.

FIG. 7 schematically shows the control system, including the main and L2 switches #81, a microprocessor 82 that performs overall control and data processing for each block, and signals and data from this microprocessor 82. It is composed of a driver 83 that creates various control signals based on the above, an AC drive system 85 driven by a commercial power supply 84, a DC drive system 86 driven by a DC power supply, and a display system 87 that displays various statuses. Ru.

Each of the hammer switch groups 81 detects the end of paper feeding by the key operation system 91 consisting of the print key 72, clear strike, go key 73, numeric keypad 74, etc., the variable resistor 76, and the paper feed roller 12. A paper end switch (P-END-Sw), a sheet switch (SHEET-) that detects manually fed paper at the feed roller 25
8Wλ and a paper engine switch (P-ENP-8W) that detects no paper in the predistribution paper cassette 11; a key switch 94 that detects insertion of a key counter (not shown); and the table. From the start switch (T-STR-SW) 45, table home switch (T-HO part-5W) 46, table limit switch (T-LIMIT-8W) 47, vapor start switch (P-8TR-SW), etc. A toner full switch (T) detects when the recovered toner in the re-reading device 22 is full
-FULL-SW), a cleaner cleaning switch that detects the Tl1t cleaning period in the front cleaning device 22, and a toner engine switch (T-ENP-SW) that detects the lack of toner in the front cleaning device 22. #-switch (EXIT-s'w) that detects the end of paper ejection at the photoreceptor dovetail thread 96 and the paper ejection roller 19.
It is constituted by a conveying thread 97 made of, etc. and,
Variable resistance 176e! <The signals from each of these switches are
The data is input to the microprocessor 82 via a data selector 98 or a notifier 99.

The front 40 AC drive system 85 includes a temperature control circuit 101, a lamp control circuit 102, and an AC control circuit 103, which are supplied with power from the current transformer power supply 84, and are controlled by the temperature control circuit 101 and provided in the front IT heat roller 18. The fixing heater 104 and the thermistor 105 detect the temperature 11 of the heat roller 18 and input the detection signal to the temperature control circuit 101. The lamp control circuit 102 controls the exposure rung 3 on/off, and the AC control circuit 103 controls the static elimination rung 23, the cooling 7/27, the motor 28, etc. on and off.

The DC drive system 86 includes a DC IT source circuit 111 that converts the transformed voltage from the 5e current power supply 84 into a DC voltage (for example, 24 th" DC voltage), and a high voltage transformer to which the power supply voltage is supplied from the power supply port 1Nr 111. 112, a charging transformer 113, a charging transformer 113, a charging circuit 114, a charging circuit 115, an 'F-tal counter 116, and the current iron bias power supply circuit 68. , transfer charger 15
, the stripping charger 16, and the static eliminator 21, respectively; the upper and lower charging transformers 113 drive the charger 6;
Full drive control.

In addition, the solenoid drive circuit 'Nr115 is a feed solenoid CP-STR-SQL) which controls the aligning roller 14, a feed solenoid CP-FEED-5QL which controls the paper feed roller 12t. J19, the feeding roller 25f: controlling G-tonlenoid (SHggT-
SQL) Z 2 o, 871 days Cleaner solenoid (C-8QL) that controls the cleaning device 22
J 21 and the foot monitoring solenoid (N-SQL) 122 that controls the heat roller 18, etc., are controlled as necessary.

The display system 87 is constituted by a display driver 4131 that receives a signal from the key operation system 91, and a latch driver 132 that temporarily latches all data from the microgrocer 82. In addition, each of the above drivers 1
31 and 132 control the lighting of the sheet count indicator 75, the operation state M indicator 78, the ready display rung 79, and the wait display run f80f, as necessary.

Next, in the above configuration, the overall operation is
This will be explained with reference to the flowcharts shown in FIGS. First, 9. When the current power source 84 is turned on, the output port and RAM (random access memory) area in the V microgross processor 82 are cleared, and then "0" is displayed on the sheet number display 75 and the wait light indicator 80 is turned on. Next, the status of the cleaner cleaning switch is checked, and if it is in the off state, an error (ERR) will be displayed, that is, the cleaner cleaning indicator lamp 18 will be lit, and if it is in the off state, the next Wr waiting time will be displayed. It is checked whether or not 5.4 seconds) has elapsed, and this process is repeated until the time elapses, and depending on the case, the paper remaining inside at this time is forcibly ejected. Then, after a predetermined period of time has elapsed, the temperature of the heat roller 18 detected by the thermistor 105 is checked to see if the state is ready for copying. The status of the next K, -?- switch 94, toner 7/I/switch, f79 remains off, and if all the switches are in good condition, the ready indicator rung 79 is lit.

Copy processing is possible in this state.

That is, after setting the number of copies using the numeric keypad 74, the copying operation is started by pressing the glint key 72. In other words, when the glint key 72 is pressed, the Freddie display rung 79 goes out and the cleaner solenoid 1
21 is turned on. After that, the motor 28 is driven after a predetermined time (approximately 0.1 seconds) has elapsed, and then, after a predetermined time (approximately 1 second) has elapsed, the fixing solenoid 122
And the high voltage transformer 112 is turned on. moreover,
At this time, the developing bias microcircuit 68 is turned on,
An AC bias voltage, which will be described later, is applied to the sleeve 6- of the developing device 7, which is set by a variable resistor 16. After a predetermined period of time (approximately 31 seconds) has elapsed, the process proceeds to a continuous copying (MULT) flow as shown in FIG.

In the flow of continuous copying of multiple sheets, it is first checked whether or not the table start switch 45 is in the OFF state, and when it is in the OFF state, the electromagnetic club, the original platen retreat club of 29, and 29 are turned on, and the original platen 2 is moved backward. Start moving. and,
After a predetermined time (approximately 0.1 seconds), total counter 1
16 is turned on, and the sheet number display 75 is turned on for counting.
The number of sheets subtracted by "l" from the set number of sheets is displayed. In this state, start paper.

It is checked whether the table start switch 45 is in the on state or not, and if it is in the off state, after a predetermined period of time (approximately 0.4 seconds) has elapsed, it is checked again whether or not the table start switch 45 is in the on state. When the condition is reached, the vapor starts again.

It is checked whether the switch is in the on state or not, and if it is in the off state, a predetermined period of time (approximately 0.75 seconds) has elapsed.
i! An error message will be displayed later.

On the other hand, if the table start switch 45 and the paper start switch are each in the on state, the predetermined time (
After about 1 second), the paper feed lenoid 119 is turned on and the turtle paper feed roller 12 operates to feed the paper feed cassette and tray 1.
Paper is fed from within 1. Then, for a predetermined time (approximately 0.
83 seconds) When passed, Paper Feton Lenoid 119
is turned off and paper feeding ends. After that, a predetermined time (i
o, 1 second), the exposure rung 3 becomes o/, and the light adjustment is started. After that, when a predetermined time (approximately 0.11 seconds) has elapsed, it is checked again whether or not the table start switch 45 is in the on state, and when the table start switch 45 is in the off state, an error message is displayed after a predetermined time (approximately 106 seconds) has elapsed. Reduce.

On the other hand, if the table start switch 45 is in the ON state, the electromagnetic clutch 2
The document table forward clutch 9 is turned on, and the document table 2 starts moving forward. After a predetermined period of time (approximately 0.18 minutes) has elapsed, the charging transformer 113 is turned on and charging processing is performed. Next, it is checked whether or not the paper start switch is in the on state. If it is in the on state, the paper start solenoid 118 is turned on and the paper feed roller 1 is turned on.
The paper P taken out in step 2 is fed by the aligning row 214 and proceeds to step 70- in FIG.
An error message will be displayed after 3 seconds) have elapsed.

As described above, when the paper P is fed by the aligning row 214 and the paper end switch detects the rear end of the MPO for feeding, the charging transformer is activated after the P9r time (approximately 0.04 seconds) has elapsed. 113 is turned off, and the charging process ends. On the other hand, when the trailing edge of the paper P is not detected, the document table 2 continues to move forward, and the magnet 4 eventually switches to the reed switch (table limit switch).
-7 will be turned on, so if it is determined that the limit, tosui, and chi 41 are turned on, the predetermined time (
An error message will be displayed after approximately 17 seconds) have elapsed. Furthermore, even if the top-distributed mitswitch 7 is in the OFF state, an error message will be displayed after a predetermined period of time (approximately 3 seconds) has elapsed.

When the charging process is completed as described above, a check is made to see if the size of the document set on the document table 2 is smaller than B5.
After T time (approximately 0.03 seconds) has elapsed, the document table forward clutch is turned off, and the movement of the document table 2 is stopped. After a predetermined period of time (approximately 1 second) has elapsed, the document table back clutch is turned on, and the document @2 starts moving backwards.
After a predetermined time (approximately 0.06 seconds), IIK original run will occur 3
is turned off. As the document table 2 continues to move backward, the magnet A4 will eventually turn on the reed switch (table home switch) 46, so when it is determined that the home switch 46 is turned on, Proceeds to 70- in Figure @11. On the other hand, when the home switch 46 is in the OFF state, an error message is displayed after a predetermined period of time (approximately 148 seconds) has elapsed.

As described above, when it is determined that the table home switch 46 is in the on state, the state of the clear stop key 73 is checked, and if it is in the off state, then it is checked whether or not the continuous copy mode is on. , when entering the continuous copy mode, the state of the key switch 94 is checked next,
When it is off, the state of the vapor engine switch is checked next, when it is on, the state of the toner full switch is checked, and when it is off, the state of the toner full switch is checked again.
Proceed to the continuous reconnaissance flow shown in the figure. However, if the clear dog key 73 is on/off, the continuous copying mode is not on, the key switch 94 is off, the vapor engine switch is off, and the toner full switch is on/off, the process proceeds to the flow of the arrow 1. The document table reverse clutch and paper start solenoid 118 are turned off. At this stage, the number of copies is restored on the sheet number display 75, and then it is determined whether or not the sheet ejection is completed by checking the state of the paper ejection switch, and the paper ejection #! If r, the 1% output transformer 112 and the developing/eliminating power supply circuit wr6B are turned off after a predetermined time (approximately 1.4 seconds) has elapsed. After that, Tokoroda hours (about 360
7 seconds), the constant monitoring solenoid 122 turns off,
The motor 28 is turned off after a predetermined time (approximately 0.7 seconds) has elapsed, and the cleaning lens 121 is turned off after a predetermined time (approximately 0.1 seconds) has elapsed, thereby completing a series of copying processes. The operation ends.

The above-mentioned copying apparatus performs program interrupt processing at predetermined intervals during program processing in order to retain program setting contents in the microprocessor 82. It is configured to do setup money.

The principle of development using the one-component high-resistance magnetic toner in the present invention will be explained with reference to FIG. #IfJ12. In FIG. 12, the magnetic toner ■ is indicated by the arrow d
Troller 65, a magnet with multiple poles rotating in the direction
It is conveyed in the direction of arrow C by the action of the rotating magnetic field of and the sleeve 64 rotating in the direction of arrow C. At this time, the magnetic toner (2) has a constant thickness due to the doctor blade 62. In addition, a positive charge is stored in the conductor L-5& of the photoreceptor drum 50 in a state corresponding to the original.
A latent wound ■ is formed.

Then, the conductive layer (aluminum material) s of the photoreceptor drum 5
b is grounded, and the sleeve 64 of the imager 7@ is also grounded via a developing bias power supply circuit 68t.

Therefore, when the positive charges stored in the photoconductor layer 5& come to the 3A image point X, the upper ml of the photoconductor layer 5b is
A negative (C) charge [F] of opposite polarity corresponding to the positive charge is generated. However, this negative charge ■ is applied to the surface of the sleeve 640 by the bulk bias power supply circuit 68, and
Development is performed by injecting a negative charge into the a-type toner (2).

Here, the principle of development at the upstream development point X will be explained in more detail with reference to FIGS. 13 to 15. 13 and 14 are simplified model diagrams of development, and FIG. 15 shows its equivalent circuit. Figure 13 and 1
In Figure 4, 65 is a magnet roller, and 64 is a three! , 66 is magnetic tonano so, 5a is motohiro's body j so, 5
B is played by each of the two players. Also, in Figure 15,
Cf is the equivalent weight of the photoconductor layer 5a, Ct is the weight of the magnetic toner layer 11#66, and R is the resistance value of the magnetic toner layer 11#66. As mentioned above, the 13th image shows the state where MiJ = e #image ■ in which the static charge Q0 has been stored approaches the magnetic toner I so 66, and the state immediately before the charge transfers to the magnetic toner J so 66. Illustrated.

In FIG. 13, a positive charge Q0 is stored in the photoacidic layer 5a as described above 9, and the potential of its narrow surface is . She is the sister of In general, in the case of high-strength antimagnetic toner, the resistor of the toner layer is larger than 66, so the photoconductor layer 6 is too large. When is low, AT note toner pigeon 6
The time constant of 6 is longer than the development time. therefore,
If sufficient charge is not transferred to the magnetic toner N66 and sufficient charge is not induced at the tip of the magnetic toner layer 66, but the surface potential v0 is still insufficient, the magnetic toner layer 6
Due to the electric field dependence of the resistance of the magnetic toner layer 66, when the pre-ml resistance R is small υ, a sufficient charge can be induced at the tip of the magnetic toner layer 66. That is, as shown in FIG. 14, the developing current flows and the charge Q is transferred from the light*'It body layer 5a to the magnetic toner layer 66. At this time, one layer of magnetic toner 6
The forces that the charged particles at the tip of photoconductor J-61 receive are a magnetic restraining force Fm in that direction by the magnet roller 65 and an electrostatic attractive force Ff in the direction of photoconductor J-61.

Then, assuming that the diameter of the particle is one foot, the magnetic binding force Frn in the direction of the magnet and troller 65 is constant, and the electrostatic attractive force Ff in the direction of the photoconductor layer 5a is the surface potential V0. is proportional to. Therefore, the surface potential V. When the value exceeds a certain value, the relationship becomes [Fm<Ff], and the tip particles of the magnetic toner layer 66 are attracted to the photoconductor)@5m,
Development is carried out by adding a layer (toner 2 in FIG. 12) to the photoconductor layer 5a.Next, referring to FIG. 16, the development noise power supply circuit 68 will be explained in detail. explain. In Figure 16, 14
1 is a well-known voltage control IC (for example, μA723 manufactured by Texas Instruments), and as shown in FIG.
2. It mainly consists of a current circuit 143, an impedance &[]1 angle 144, an error amplifier (differential amplifier) 146, an output control transistor 146, and the like.

Further, 141 is the DC power supply circuit 111 (see FIG. 7).
A power supply terminal to which WE source voltage + VCC is supplied from 14
Reference numeral 8 denotes a ground terminal connected to the ground line of the power supply circuit 111. Therefore, the resistance 149.150 and PN
P) Turn on transistor xszd development/earth voltage
It constitutes an off control circuit. That is, resistance 149.
150 are connected in series, one end of which is connected to the tIIL source terminal 1.
47, and the other end is connected to the remote signal terminal 162. The connection point between the resistors 149 and 150 is connected to the base of a transistor 1510, the base of this transistor 151 is connected to the power supply terminal 147, and the collector is connected to the power supply terminal Q of the voltage control IC 141.
and ``are respectively connected to the collector terminal of the output control transformer 146.

On the other hand, resistors 153 and 154 are connected in series between the reference voltage generation terminal ■ of the voltage control ICJ4Z and the ground terminal 148, and the connection point between these resistors 153 and 156 is connected to the voltage control IC141. Connected to the non-inverting input terminal ■, this terminal ■
A capacitor 155 is connected between the ground terminal 148 and the ground terminal 148 for voltage stabilization and startup functions. The resistor 154 is connected to the variable resistor 7.
6 and a resistor 176 are connected in parallel. Also, a frequency compensation capacitor 156 is connected between the inverting input terminal ■ of the voltage control ICI 41 and the frequency compensation terminal 0.
and a diode 152 of inertia shown in the figure are connected in series, and the upper inverting input terminal (2) is connected to a slider of a variable resistor 158 for adjusting the output voltage M. Furthermore, voltage control IC
The output terminal of 141 is connected to the pace of an oscillation suppressing NPN transistor 161 via resistors 159 and 160 in series, and the emitter Fi of this transistor 161 is connected to the ground terminal No. 8, and the collector is connected to the external voltage. It is connected to the power supply terminal 147 via the primary winding 163 of the transformer 162 . The connection point between the resistors 159 and 160 is connected to one end of the oscillation winding Iwi1164 of the step-up transformer tex, and a voltage flag diode is connected between the other end of the oscillation winding 16I and the ground terminal 148. 165 and an oscillation capacitor 166 are connected in parallel. ball,
The output winding 161 of the external pressure transformer 162 (one end of D is connected to the bias voltage output terminal 168, and the other end is used for protection in case of short circuit)
It is connected to the ground terminal 170 through a resistor 169. Here, the output terminal 168 is connected to the power supply blade 61 (see FIG. 5) of the developer@7, and the ground terminal 170 is connected to the ground terminal 14&, and the main body 1 (see FIG. 1). (see).

Furthermore, the output voltage detection winding 17 of the external pressure transformer 162
1 is connected to the ground terminal 170, and the other end is connected to the ground terminal 170 via a rectifying diode 172 and a smoothing capacitor 173 in series. The connection point between the diode 112 and the capacitor 173 is a resistor 17-
nl connected to one end of the variable resistor 158 through this variable resistor? The other end of 515g is connected to ground terminal 170 via resistor 175. As a result, the detection winding 171
The output voltage of
The voltage is divided by the variable resistor 158 and the variable resistor 158
The slider voltage is applied to the inverting input terminal (2) as an appropriate feedback voltage Vfb.

The operation shown in FIG. 16 in such a configuration will be briefly explained. Now, when the remote signal terminal 152 becomes low level, the transistor 151 turns on, and the voltage control IC 14
The power supply voltage +vcc is supplied to each terminal @ and (2) of the voltage control IC 141, and the voltage control IC 141 starts operating. Therefore, the reference voltages vr and f are output to the reference voltage generation terminal (■) of the voltage control ICI 41, and the resistor 153 and the variable resistor 7
6 and resistors 176 and 154, and then applied to the non-inverting input terminal @. At this time, the non-inverting input terminal ■
The voltage gradually rises with a certain time constant due to the action of the capacitor 155, and rises to a voltage commensurate with the above-mentioned divided voltage. In addition, immediately after the remote signal terminal 152 becomes low level, the feedback voltage Vfb is zero volts. Therefore, since the voltage at the inverting input terminal ■ is lower than the voltage at the non-inverting input terminal ■ of the voltage control IC 141, Output terminal [phase]
The voltage of transistor 161 becomes high level.
When the pace current flows and turns on, current flows through the primary winding 163 and a predetermined voltage is generated at the output winding 167. The transistor 161 operates to repeat an on-off operation by a feedback voltage of a predetermined constant period generated by the oscillation winding 164 and the capacitor 166, so the output winding 167 is supplied with a current-changing developing bias. A voltage vD1v is output.

This developing bias voltage VIImV is applied to the detection winding 171
The error angle 145 and the output control transistor 146 (
(see FIG. 17), the voltage value is always constant.

Therefore, by changing the voltage of the non-inverting input terminal (2), the p1 developing bias voltages VD and vk can be changed. In this embodiment, since the variable resistor 16 for original density gu and the resistor 116 are connected in series between the non-inverting input terminal 2 and the ground terminal 148, the variable resistor 7
By changing the resistance value of 6, the non-inverting input terminal ■
The voltage also changes. That is, when the resistance value of the variable resistor 16 is increased, the output voltage (developing) 4 Ias voltage) Vn
When i+v increases and becomes smaller, the output voltage VDIY decreases.

In this way, the effect of the developing/dead biasing pressure VDBY outputted from the developing bias power supply circuit 68, especially the relationship between original density and copying # change (so-called r characteristic), can be evaluated as follows.
This will be explained with reference to FIG. 8 and FIG. 19. FIG. 18 shows the surface vLtγ■ on the photoconductor layer 5&. This is a diagram showing the relationship between the developing bias voltage (wave number is 800 Hz) and VDIV, and FIG. 19 shows experimental data showing the relationship between original density and copy density when the developing bias voltage VDII/total change is made. be. First, although the principle of development has been described above, here we will discuss changes in development conditions when a development bias voltage is applied. In FIG. 18, when an AC developing bias voltage VDIV is applied to the sleeve 64 of the developing device 7, the strength of the electric field applied to the magnetic toner layer 66 changes in synchronization with the bias voltage "DIV". At point 9 in the figure (a positive voltage is applied to the sleeve 64), the strength of the electric field is weaker than when no developing bias voltage VBIV is applied, and at point f (a negative voltage is applied to the sleeve 64). On the contrary, it becomes stronger.

Therefore, at point f, the electric field becomes stronger, so that the developing bias voltage V1. The charge is more easily transferred to the m-type toner layer 66 than when V is not applied. Also, 0
Conversely, charge transfer occurs at the point, and a force acts to attract the negatively charged toner to the three zeros 4. In this way, when the developing bias voltage .mu.nmv is applied, the action of promoting the development gI and the action of inhibiting it work mutually depending on the state of application of the voltage.

@Figure 19 shows experimental data when the amount of light applied to the original was kept constant, so the value of the original density and the surface potential of the photoconductor layer 5a (■). There is a proportional relationship. As shown in the figure, when the current salary bias voltage vDlvf is gradually raised from zero,
The r characteristic curve shifts to the left as a whole, and shifts to the farthest left when a voltage of about 500 volts is applied. That is, in this state, it is shown that the copy density becomes higher when the developing bias voltage VDIV is applied even for a W document having the same density. Then, the developing bias voltage v11. When increasing v1 to 500 melt or more, the rate of change of the r% curve becomes gradual.

Here, in FIG. 19, the curve 4iA is when the development/irradiation pressure is 4 at the bottom, the curve B is at 100 & 200 degrees, the curve -C is at 200 degrees, the curve is at 500 melt, and the curve E is at 8
At 00 & rut, curve F shows each IvI property at 1000 & rut. The following is true from the above data. When the developing bias voltage vDIY reaches about 500 gelts, the rate of change of the r characteristic curve does not change much and shifts to the left as a whole. This is very similar to the case where the exposure amount is changed by a small amount without applying the developing bias voltage vDmvt. Also, the developing bias voltage vD,, 1500♂
When it is placed on silt, the rate of change of the γ% characteristic curve changes depending on the voltage [K. In other words, the gradation with respect to the original density improves.

As explained above, when the developing bias voltage VmlV is varied, the effect of promoting development due to the negative voltage (point f) in FIG.
00yj? There is also the effect of negative voltage at voltages above the default, but
Rather, it is possible to change the rate of change of the working color and r characteristic curves together with the effect of inhibiting development due to a positive voltage (0 point).

In addition, by applying an AC developing bias voltage vDlv to the sleeve 164 of the developing device 7 and giving vibration to the magnetic toner, good conveyance of the magnetic toner on the sleeve 64 is achieved, and the rotation of the magnetic roller 65 improves the conveyance of the magnetic toner. It is possible to correct changes in the suction force, etc., and to significantly reduce unevenness at the time of actual injury.

Next, regarding document density adjustment using the developing bias voltage VD*ma, which is the gist of the present invention, FIGS.
-Refer to and explain. As described above in FIG. 19, when the light cover for irradiating the original is kept constant, the voltage applied to the sleeve 64 of the developing device 7 is θ~500? Up to the maximum value, the ratio of the rate of change of the r% curve does not change much, but shifts to the left as a whole, which is very similar to the case where the exposure amount is changed. Therefore, the applied voltage 1E to sleep 6-
(i image bias voltage vDIV) 't' variable resistor 7
6, the same result as when I9 and the light lft of the exposure rung 3 is changed can be obtained. Second
In Figure 0, as mentioned above, the developing bias voltage V□V is set to 100~
In Figure 0, which shows a specific 1% property curve when changing up to 500 melts, curve G is stable when the developing bias voltage is 100 melts. ! For an original at 14 degrees, curve H is the same as curve L for an original at standard density with a developing bias voltage of 200 gelt.
1 and 2 respectively represent the case of an i draft with a developing bias voltage of 500 melt and a light density.

Note that the %r characteristic curves G, H, and I in Fig. 20 are standard to match the copying density of the original once, and the r% characteristic curves B, C, and D in Fig. 19 are set by increasing the exposure IT. Shift it to the right.

By providing the bias voltage control means 1c as described above, a similar effect can be obtained; that is, the original horizontal dlf
#Exposure rung 3 can be
control can be greatly simplified. For example, since the exposure lamp 3 is required to be turned on and off, the control circuit for the exposure lamp 30 becomes very simple and costs can be reduced. Furthermore, since the power supplied to the exposure rung 3 is not variably controlled, the light source spectral distribution due to variable power of the exposure lamp 3 is stabilized, and changes in sensitivity of the photoreceptor drum 5 can be significantly reduced. Furthermore, by applying an alternating current bias voltage to S')-f64 of the developing device 7, the developing conditions can be adjusted, and development unevenness (density change) can be kept low, especially at low densities.

[Effects of the Invention] As detailed above, according to the present invention, a bias voltage control means for variably controlling the bias voltage to the developing device as necessary is provided, and by variable control of the developing bias voltage by this control means, By configuring the document density adjustment, the document density [1111! Since there is no need to control I on the exposure rung side, exposure rung control can be greatly simplified, and furthermore, the shadow on the photoconductor due to the original density f-adjustment can be significantly reduced, and other effects can be expected. Copying equipment can be provided.

[BRIEF DESCRIPTION OF THE DRAWINGS] The drawings show one embodiment of the present invention, and FIG. 1 is a diagram 1111f1 showing a schematic configuration of an electronic copying device, and FIG. FIG. 3 is a schematic side view for explaining the moving position detection mechanism of the document table;
Figure 4 shows the configuration of the current gI device in detail.
The figure is a schematic 1i111 side view for explaining the 4ias voltage application method and 4aa) toner conveyance state of the developing device.
The figure is a plan view showing the operation nocinele in detail, and Figure 7 schematically shows the control system! Lower Figure 2, Figures 8 through 8g11 are flowcharts for explaining the operation, Figure 12 is a schematic side view for explaining the embedding process of development using a one-component pseudo-resistance magnetic toner system, and Figures 13 through 11 are flowcharts for explaining the operation. Figure 15 is for explaining the above IjA principle of development in more detail.
Figures 1 and 14 are simplified development model diagrams. i@
Fig. 15 is an equivalent circuit diagram thereof, Fig. 16 is a block diagram showing details of the fA bias power supply circuit, Fig. 17 is a schematic block diagram of the voltage control IC in Fig. 16, and Figs. 18 and 19.
The figure is for explaining the effect of developing bias voltage.
Figure 18 is a diagram showing the relationship between the surface potential of the photoreceptor drum and the developing bias voltage, and Figure 19 is the relationship between original density and copy density when the developing bias voltage is completely changed (1%).
FIG. 20 is a specific characteristic curve diagram showing the 1% property when the developing bias voltage is changed. 2... Original table, 3... Exposure rung, 5... Photosensitive drum, 6... Charger, 7... Developer, P... Paper, 15... Transfer charger , 18...Heat roller (foot layer), 63...Developing roller, 64...Sleeve, 65...Magnet roller, 67...Power supply plate r168...Developing bias power supply circuit, 7th . . . Operation panel main body, 12 . . . Print key, 76 . . . Sliding variable resistor for original a11 degree pAu, 82 . Applicant's agent Patent attorney Takehiko Suzue Figure 12 Figure 13 I! Figure 14r. Figure 15

Claims (1)

[Claims] In a copying apparatus in which copying is performed through each process of charging, exposure, and development, and the boundary image growth uses a one-component developer, the bias voltage to the developing device in the pre=a development process can be controlled as necessary. The copying apparatus is characterized in that it is provided with a bias voltage control means 5I, and is configured to perform wI4 adjustment once on the original by variable control of the bias voltage by the bias voltage control means.