JPS63267967A - Image forming device - Google Patents

Abstract

PURPOSE:To immediately replenish a toner, by displaying the empty state when at least one of respective toner replenishing tanks from which the toner is replenished to a selected developing device is empty of the toner. CONSTITUTION:If at least one of toner replenishing bottles 81 and 91 is empty of the toner when the 1s2c copy mode is selected, a toner empty indicator LED 132 is lit to inform a user that it is necessary to replenish the toner. In case of the color copy mode, it is discriminated whether the toner replenishing bottle 81 for a color (first) developing device is empty or not, and the toner empty indicator LED 132 is lit if it is empty, but otherwise, the toner empty indicator LED 132 is extinguished. Thus, the toner is immediately replenished.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an image forming apparatus equipped with a plurality of developing units.

(Background of the Invention) Conventionally, image forming apparatuses have been provided in which a plurality of developing units each containing a developer of a different color are arranged around a photosensitive drum which is an electrostatic latent image carrier. This type of image forming apparatus is provided with a toner empty indicator lamp, and when the toner replenishment tank of the selected phenomenon device becomes toner empty, the toner empty indicator lamp is lit to indicate that toner should be replenished. I have to.

However, when performing two scanning operations and changing the developer used for each scan to obtain a composite copy, as proposed by the present applicant in Japanese Patent Application No. 62-015572, , in the case of a multicolor image forming mode in which a multicolor copy is obtained by driving different developing devices for each of multiple areas divided by a designated point during one scan operation, one image is generated. A plurality of developing devices are selectively used during the forming operation.

Therefore, at this time, if only the toner empty state of the toner replenishment tank attached to one of the developing devices is displayed, even if the toner replenishment tank of the remaining developing device becomes empty, it will not be displayed. It will not be displayed. Furthermore, if toner empty display means are provided in a number corresponding to the number of developing units, the cost will increase accordingly.

(Means for Solving the Problems) The present invention has been made to solve the problems mentioned above.
In an image forming apparatus in which a plurality of developing units each containing a developer of a different color are arranged on the side of an electrostatic latent image carrier, 1
g, each toner replenishing tank is provided with a toner empty display means and replenishes toner to the selected developing device during an image forming mode in which a plurality of developing devices selected during one image forming operation are used; If at least one of the toners is empty, the empty state is displayed by the empty display means.

(Example) Hereinafter, an example of the present invention will be described with reference to the accompanying drawings.

(1) Configuration First, the configuration of the copying machine will be explained.

i. Overall configuration The copying machine (1) has the configuration shown in FIG. 1, and the photosensitive drum (2) is approximately located in the middle and can be rotated counterclockwise by a main motor (not shown). Around it, at intervals in the rotational direction, a charger (3), an inter-image eraser (4), a first developer (5), and a second developer are arranged in order.
Developing device (6), transfer camera (7), separation belt (8)
), a cleaner device (9), and a main motor (10) are arranged, and an optical system (0) and a movable document table (20) are arranged above the photoreceptor drum (2) and the peripheral equipment, and on the left side. is the paper feed system (30), the fixing device (4), and the paper ejection unit (4) are on the right side.
2) are provided respectively. Note that three or more developing devices may be provided.

1! , optical system (0) The optical system (0) is composed of a slit exposure type light source (11), mirrors (12) to (15), and a lens (16), each of which is fixed as shown in the figure. The reflected light irradiated from the light source (11) onto the document table (20) passes through the path shown by the dashed line, and is applied to the surface of the photoreceptor drum (2) by the charger (3) and the eraser lamp. (・1)
It is designed to be exposed to light from between.

111, Document table (20) The document table (20) is composed of a document table glass (20) and a document holding plate (22) that can be opened and closed on the surface thereof, and is configured to scan in the direction of the arrow. The moving speed 2 is the circumferential speed of the photoreceptor drum (2) V. , if the copying magnification is shifted by m, then V=V, , is set to 7m.

On the operation side of the document table (20), as shown in FIG. 2, on the side of the document table glass (21), there are a start point mark (A), point marks (IP) to O
P) are marked at 30 mm intervals. These marks (A
), (IP) to (OP) are for specifying the switching point of the phenomenon color in the 152c copy mode. Note that (B) is a reference point for determining the position of the original (G) when actually copying.

A position value switch (23) and a registration switch (24) are provided below the document table (20), and the document table (20) touches the position value switch (23) during non-scanning (when stopped). Press the registration switch (24) to output a localization value signal to the 10th PU (200), which will be described later.At the same time, when the original platen glass (21) has scanned a predetermined distance, touch the registration switch (24) to output the localization value signal to the 10th PU (200), which will be described later. , and 1s2 for operating a timing roller (35) to be described later.
During c-copying, a registration signal is output for switching between the developing devices (5) and (6).

iv. Paper feeding system (30) The paper feeding system (30) includes a manual paper feeding section (31), a first cassette paper feeding section (hereinafter referred to as the first paper feeding section (32)), and a first paper feeding section (328, simply referred to as the first paper feeding section (32)). 2 cassette paper feed section (33) (hereinafter simply referred to as the second paper feed section (33)), and a manual paper feed section (
The copy paper inserted from 31) is conveyed to the timing roller (35) via the intermediate roller (34), and then
First and second paper feed sections (32).

Cassettes (32a) and (33a) attached to (33)
The copy paper inside is conveyed to a timing roller (35) via a first paper feed roller (32b) and an intermediate roller (34), or a second paper feed roller (33b), respectively.

Each of the rollers (32b), (33b), (34), (3
5) are detachably connected to the drive system by the main motor via clutches (not shown), and by turning on the clutch of each roller, the roller is connected to the drive system and driven by the main motor. Rotationally driven. In addition,
In the vicinity of each cassette (32a), (33a), size detection sensors (36a), (3
7a) and each cassette (32a).

A cassette empty sensor (38) detects when the copy paper in (33a) is completely consumed.

(39) is installed.

■ Operation panel At the top of the copier (1) is the operation panel (+) shown in Figure 3.
00), and the operation panel (100) is equipped with a print switch (102) for instructing the start of copying, an interrupt key (+03), a print switch (102) for instructing the start of copying, an interrupt key (+03), and a print switch (102) for instructing the start of copying, as well as an interrupt key (+03) for printing immediately after starting copying or for multi-copying (multi-copying of multiple sheets based on the same original). Copying is stopped midway through (continuous copying), and the copy number display section (1
04) Clear the number of copies set in “Standard mode”
Clear/stop key (c/s key) (105
), numeric keys (106) to (115) for setting the number of copies on the copy number display section (104), and the light source (11).
A switch (1) that selectively selects between the exposure volume (VR), which manually increases or decreases the exposure amount, and the automatic exposure mode, which automatically provides the optimal exposure amount for the original.
17), a paper feed section selection key (not shown) for selecting the first or second paper feed section (32) or (33), and displaying the size of copy paper fed from the selected paper feed section. Size display LE
D (not shown), the first developing device (5) or the second developing device (
6) and a color selection key (121) for selecting the developer device (5) or (6), and an LED (+
27), (126), and an LED that indicates when the toner supply bolt (81) or (91) attached to the selected developing device (5) or (6) is empty. (+32), book division mode selection key (
122), an LED (+28) is provided to indicate when said book split mode is selected.

Furthermore, although not shown, it has a drum dryer and a drum dryer for starting forced toner replenishment. −
vi, the developing devices (5) and (6) are composed of toner and carrier.
First, with reference to FIG. 4.5, the second developing device (6), which is a powder developing type developing device that uses component developers and is located on the downstream side with respect to the rotational direction of the photosensitive drum (2). I will explain. Note that the symbols in parentheses correspond to the first developing device (5).

(a) Structure of the second developing device (6) In the second developing device (6), a developing sleeve (61) is provided in the oil portion of the casing (60) and can be driven to rotate facing the photoreceptor drum (2). The developing sleeve (
61) is applied with a developing bias (-+50V). A magnetic roller (62) is fixed inside the phenomenon sleeve (61) and has a magnetic pole (S) in the axial direction.

A plurality of magnets with the same polarity (S, A magnetized portion (Z) is formed.

Conveyance paths (63) and (6) are located behind the developing sleeve (61).
4) are formed, each having a packet roller (65),
A conveyance roller (66) is rotatably provided.

In addition, the conveyance paths (63) and (64) are the casing (60)
Although it is partitioned off by a partition wall (67) that partially extends upward, it is connected via a passageway (not shown) formed by cutting out the back and front sides of the partition wall (67).

Further, at the bottom of the rear conveyance path (64), a toner concentration detection sensor (hereinafter referred to as "FATDC sensor") (AS2) detects the toner concentration in a two-component developer consisting of toner and carrier as a change in magnetic permeability. ) is attached so that its sensor surface is in contact with the developer in the conveyance path (64), and the output signal is output from the control circuit 1 CP, which will be described later.
It is configured to output to U (200).

By the way, like the copying machine (1) according to the present invention, there are a plurality of developing devices (5), (6) around the photoreceptor drum (2).
When developing using the first developing device (5), the developing agent in the second developing device (6) is transferred to the photoreceptor drum (2).
, the toner image formed on the surface of the photoreceptor drum (2) by the first developing device (5) is disturbed. Furthermore, when developing using the second developing device (6), if the developer in the first developing device (5) is in contact with the photosensitive drum (2), the developer on the photosensitive drum (2) may The electrostatic latent image is first developed by a first developing device (5) to mix colors.

Therefore, as a first means to prevent color mixing, the second developing device (6) includes a developing sleeve (61) and a packet roller (
A hokiri nyatta (71) is provided between the hokiri nyatta (71) and the first developing device (5).
1) is used to remove the developing agent held on the surface of the developing sleeve (second developing sleeve
The switching means (70) shown in the figure allows switching between the states shown in FIGS. 4 and 5.

(b) Switching means (70) In the switching means (70) shown in FIG.
) is rotatably attached to the casing (60), and a lever (73) is fixed to one of the support shafts (72). A spring (74) whose one end is locked to the casing (60) is locked to the tip of the lever (73), and while the lever (73) is always biased in the direction of arrow (a), the solenoid (75) ) is rotatably connected to a plunger (76) to maintain stable deafness. In addition,
(77) is a stopper.

Therefore, the ear cutting shutter (71) is connected to the solenoid (7
5) is in the off state, it is biased by the spring (74) and set to the state shown in FIG. 4 (off state),
When the solenoid (75) turns on and rotates in the direction of the arrow (ao) against the spring (74) until the lever (73) contacts the stopper (77), the state 8 (on state) shown in Fig. 5 is obtained. Set.

(c) First developing unit (5) The first developing unit (5) has almost the same configuration as the second developing unit (6), and its configuration and components are the same as those of the fourth and fifth developing units.
In the figure, the symbols in parentheses indicate the second developing unit (
6), the casing (50) has a conveyance path (53).
, (54) are formed with the partition wall (57) as a boundary, and a developing sleeve (51), a magnetic roller (52), and a packet roller (
55), a conveyance roller (56) are accommodated as shown in the figure, and an ATDC sensor (
ASI) is fixed.

However, the first developing device (5) is not equipped with a brush-cutting device (71), and as a second means for preventing color mixing, the first developing device (5) has a developing bias voltage (first developing device) applied to the first developing sleeve (51). development bias) (not shown) or two stages (-150
V, -300V)1. : They differ in that they can be switched. Therefore, the switching means (70) for the ear cutting shutter (7I) shown in FIG. 7 is not provided.

Also, 1st. Although the second developing devices (5) and (6) are driven and connected to a main motor (not shown), either one of the developing devices (5) or (6) is controlled by a sleeve solenoid (not shown).
This is a configuration in which drive is selectively transmitted only to.

That is, when the first developing sleeve (51) is drivingly connected, the driving force is not transmitted to the second developing sleeve (61), and conversely, when the second developing sleeve (61) is drivingly connected, the driving force is not transmitted to the second developing sleeve (61). The first developing sleeve (51) has a structure in which no drive is transmitted.

(d) Toner supply mechanism and toner color detection mechanism 1st.
FIG. 6 shows a toner replenishment mechanism for replenishing toner to the second developing devices (5) and (6). In addition, the code in parentheses in the figure is the second
It corresponds to the developing device (6), and the reference numeral outside parentheses corresponds to the first developing device (5), and the reference numeral of the first developing device (5) will be used in the explanation of the configuration.

A bracket (80) is attached to one longitudinal end of the developing units (5), (6), and the rear conveyance path (54) in the developing units (5), (6) is attached to the bracket (80). A toner replenishment bottle (81) for replenishing toner is detachably attached to the toner replenishment bottle (81), and is rotated by a replenishment motor (not shown) to replenish toner.
A bottle presence/absence detection sensor (82) is provided near 1), and it is determined whether or not the bottle (81) is attached based on the on/off signal of this bottle presence/absence detection sensor (82). be.

The toner replenishment bottle (81) has a replenishment port in the toner replenishment bottle (81).
A toner empty detection sensor (83) is attached to detect the presence or absence of toner within ).

At the top of the developing units (5) and (6), there are respective casings (
Magnets (84) and (85) are attached adjacent to each other in order to determine the color of the toner contained in the toners 50) and (60).

On the other hand, the main body of the copying machine includes the developing device (5).

(6) is attached, the magnets (84), (
85) facing the first. Second reed switch (86).

(87) is provided, and as shown in the table below, the first
, the color of the toner contained in the developing units (5), (6) is determined based on the combination of on/off signals of the second reed switches (86), (87).

Incidentally, in this embodiment, the second developing device (6) is fixed exclusively for use with black toner, and only the first developing device (5) can be replaced.

Therefore, when the second developing device (6) is attached, the reed switches (96) and (97) both output ON signals. Further, for example, if the first developing device (5) contains red toner, the first developing device (5) contains red toner.
Magnet (84) compatible with reed switch (86)
The magnet (85) corresponding to the reed switch (87) is not attached, and only the first reed switch (86) is turned on.

(e) In the developing devices (5) and (6) having the above-described configuration, a two-component developer consisting of toner and carrier is contained in the casing (70), and the first developing device (5) Either color toner or black toner is stored in the second developing device (6).

The developer is transferred to the transport path (5) based on the rotation of the transport rollers (56), (66) and the packet rollers (55), (65).
4), (53), (64), (63),
At this time, the toner and carrier are mixed to prepare a two-component developer having a uniform density, and the toner is charged by frictional contact between the two.

In addition, some of the developer is removed from the developing sleeve (5) during the conveyance process.
1), (61), and the magnetic roller (52)
, (62) are held in a magnetic brush state along the lines of magnetic force generated from them.

The developer held on the surfaces of the developing sleeves (51) and (61) is conveyed in the direction of the arrow in a magnetic plan state based on the rotation of the developing sleeves (51) and (61), and is brought into contact with the photoreceptor drum (2). At the opposing portion, the magnetic planar slides on the surface of the photoreceptor drum (2), and the voltage between the surface potential of the photoreceptor drum (2) and the developing bias applied to the developing sleeves (51) and (61) is increased. Based on the difference, the photoreceptor drum (
2) is transferred to the electrostatic latent image formed on the surface and made into a visible image.

The developer that has passed through the portion facing the photoreceptor drum (2) is then conveyed in the direction of the arrow based on the rotation of the developing sleeves (51) and (61), and is transported to the packet rollers (55) and (6).
5), the developing sleeve (51) is affected by the repulsive magnetic field formed in the homopolar magnetized part (Z).
It separates from the surface of (61) and conveys paths (53) and (63).
) is mixed into the developer.

By the way, in the second developing device (6), the ear cut gloss (71)
Therefore, when the developing device (6) is driven with this panicle shutter (71) in the "off state" shown in FIG. 4, the packet is released from the packet roller (65) toward the developing sleeve (61). The developed developer is guided by the spike shutter (71), advances in the arrow (X) direction, and reaches the developing sleeve (61).
At the same time, the developer released from the developing sleeve (61) passes under the ear-cutting shutter (71) and follows the arrow (
Y) is collected in the conveyance path (63).

However, when the ear cutter (71) is in the "on state" as shown in FIG. The developed developer is blocked by the spike vine (71) and returns in the direction of the arrow (X゛), and reaches the developing sleeve (61).
) is not supplied to the surface. Further, the developer held on the surface of the developing sleeve (6I) is collected into the conveyance path (63) in the same manner as described above, and the developer held on the surface of the developing sleeve (61
) is said to have almost no developer on it. Therefore, even if development is performed using the first developing device (5) in this state, the toner image formed by the first developing device (5) will not be disturbed.

In this way, the developing operations are repeatedly executed in the developing devices (5) and (6), so that the developing devices (5) and (6) are repeatedly executed.
The toner in 6) is gradually consumed and the toner concentration decreases.

Then, the ATDC sensor (A S l ), (A S2
), the toner replenishment bottle (81) of the toner replenishment mechanism is detected by a signal output from the microcomputer, which will be described in detail later.
, (91) to the conveyance paths (54), (64), and this newly replenished toner is transferred to the conveyance roller (54).
6), (66) and the transport paths (54), (53), (64) based on the transport action of the packet rollers (55), (65).
), (63), and is mixed with a carrier to prepare a two-component developer.

v111 circuit configuration The copying machine (1) has a built-in microcomputer (not shown), and the microcomputer has a circuit configuration as shown in FIG.

In the figure, the microcomputer includes first and second CPUs (200) and (300), of which a first CPU
The PU (200) includes various keys on the operation panel (100), the first . Second presence sensor (83), (93), first presence sensor (83), (93), first presence sensor (83), (93), first presence sensor (83), (93); Second bolt empty sensor (82).

(92), reed switch (84) that detects toner color
, (85), (94), (95), etc. are arranged vertically and horizontally.
), (AS2), position value switch (23), and registration switch (24) are connected, and the aforementioned main motor, various roller clutches, etc. are connected to the first CPU (200) based on the operation of each key or the operation of sensors. ) is operated and controlled by the copy number display unit (104) ((104a), (+04b):
Various LEDs of the first class are turned on and off.

On the other hand, the second CPU (300) is connected to the localization value switch (23), the registration switch (24), etc., and this second CPU (300) mainly operates and controls the optical system (0). Menu 1st CPU (200) and 2nd CPU
(300) are connected to each other for mutual synchronization.

11.1 Yot 2 Color Copy (LS2C Copy) Next, use the copying machine (1) configured as described above to reproduce an area divided into two in the scanning direction in a different color in one scan operation. 2 color copy (1s2c
This section explains the operation when performing copying.

i. Setting the switching point Ru.

As shown in FIG.
) to match the starting point mark (A) and set the desired color switching point (Po).

For example, color the area (R1) to the right of the dotted line,
When developing the left region (R2) in black, set "4P" corresponding to the dotted line as a switching point (Po), and press the color selection switch (121), numeric keypad (+06), . , (+15) to input.

Next, the original (G) is turned upside down so that the image surface is facing down, and the left end of the original (G) is set to match the reference point (B), as shown by the dashed line on the left side of the figure.

ii. Copying operation With the original (G) set as described above and the copying machine (1) set to the 152c copy mode in a manner to be described in detail later, 1s2c copying is performed as shown in FIG. Executed according to timing chart.

Note that in the initial state of the copier (+), the Hokiri shutter (7
The switching means (70) of 1) is set to the OFF state shown in FIG. 4, and the drive of the main motor is set to the black copy mode in which the drive can be transmitted only to the second developing device (6).

First, the print switch (+02) is turned on, and when the on-edge is detected, the main motor starts driving and the photosensitive drum (2) starts rotating in the direction of the arrow, and at a predetermined timing, the charging charter (3) starts rotating. ), transfer chart (7), light source (!■), etc. are turned on.

Then, an inter-image eraser (4) is used to erase the area between the images of the photoreceptor drum (2), that is, between the original platen glass (21) and the original holding plate (22).
) on the surface of the photoreceptor drum (2) with the charger (3), on the premise that the charge in the area before the front edge in the scanning direction and after the rear edge in the scanning direction of the document (G) set between the The area corresponding to the original (G) is charged.

On the other hand, along with the ON operation of the print switch, the ear-cutting shutter-on delay timer (Tsh-A) is set, and when the ear-cutting shutter-on delay timer (Tsh-A) ends, the second
Solenoid (75) of switching means (70) of developing device (6)
is turned on, the ear cutting shutter (71) is switched to the on state shown in FIG. 5, and the ear cutting operation for removing the developer on the surface of the second developing sleeve (61) is started. Note that the ear cutting operation is controlled by a timer (Tsh-
A) It is the second developing sleeve (61) that is delaying the time.
This is because the ear cutting operation is started in a state where the rotation has sufficiently increased.

When the brush-cutting glosser (71) is turned on, the sleeve rotation black toner removal timer (Tsh-B) is then set, and after waiting for its completion, the drive of the main motor is switched to the first developing unit (5) by the sleeve solenoid. The color copy mode is set, and the first developing device (5) starts driving, while the driving of the second developing device (6) is cut off, and the first developing device (6) starts driving.
5) The developing bias is switched from the black level (-300V) to the color level (-150V), and the! Developer (
5) is set to a state where development is possible.

When the peripheral devices for the photosensitive drum (2) are set as described above, the light source (11) is turned on and the document (G) is scanned while the document table (20) is moved by a scanning motor (not shown).
By scanning the image, an electrostatic latent image corresponding to the original image is formed on the photoreceptor drum (2).

When this electrostatic latent image reaches a portion facing the first developing sleeve (51) based on the rotation of the photoreceptor drum (2), the electrostatic latent image is formed on the first developing sleeve (51).
A magnetic brush of color toner formed on the surface of the developing sleeve (51) is rubbed and visualized.

This color toner image is then transferred to the second developing sleeve (61
), but within the time of the timer (Tsh-B) before the scanning operation is started,
Since the developer containing black toner on the surface of the second developing sleeve (61) has been almost completely removed, even if the color toner image passes through the part facing the second developing sleeve (61),
The toner image does not come into contact with the magnetic plan of the black developer and the image is not disturbed.

Next, when the document table (20) is scanning and the registration switch (24) is touched and turned on, the timer (Ts
c-A) is set. This timer (Tsc-A) varies depending on the distance from the leading edge of the document to the color switching point (Po), and is internally controlled based on the switching point (Po) data input by operating the keys on the operation panel (100). When the timer (Tsc-A) times up, the switching point between the area (RI) and (R2) of the document (G)
One point of the electrostatic latent image corresponding to the first developing sleeve (51) is set so as to be about to pass through the portion facing the first developing sleeve (51). The timer (Tsc-
The value of A) will be explained later.

Note that the output signal from the registration switch (24) is sent to a timing roller (
35) to decide the start timing.

When the registration switch (24) is turned on, the timing roller (35) starts driving, and the copy paper that had been waiting in front of the timing roller (35) moves to the transfer area [
The photoreceptor drum (2) and the transfer charger (7) are conveyed to the opposing portion.

When the timer (Tsc-A) expires, that is, when one point of the electrostatic latent image corresponding to the switching point (Po) passes through the part facing the first developing sleeve (51), the sleeve solenoid stops the main motor. The drive is driven by the first developing unit (
5) to the second developing device (6).
), and the bias voltage of the first developing device (5) is switched from -150V to -300V. Also, when the timer (Tsc-B) is set and this is finished, the second
The panicle shutter (71) of the developing device (6) is set to the OFF state again. Note that the value of rima (Tsc-B) will be explained later.

In this way, the switching operation of the cutting shutter (71) is delayed by the time of the timer (Tsc-B) because the color switching point (Po) passes through the part facing the first developing device (5). At this point, the rear end of the color toner image developed by the first developing device (5) is still on the second developing sleeve (61).
The sleeve solenoid and the first developing bias are switched at the same time as the ear-cutting shutter (
71) is turned off, the color toner image will be disturbed by the magnetic brush formed on the second developing sleeve (61).

Due to the off operation of the ear cutting shutter (61), the region (R2)
Black toner is supplied from the second developing device (6) to the electrostatic latent image corresponding to the region (R2), and the timer (T
sc-C) starts.

Note that the electrostatic latent image formed on the surface of the photoreceptor drum (2) passes through a portion facing the first developing sleeve (51) before reaching a portion facing the second developing sleeve (6I). However, the drive of the first developing device (5) is cut off, and the first developing bias is set to -15 during color development.
0V) is higher than (-3o ov)t, which increases the binding force on the color toner on the first developing sleeve (51), so even if the color developer comes into contact with the electrostatic latent image, However, no color toner is transferred to the electrostatic latent image.

When the timer (Tsc-C) counts up, the area (
In this way, the electrostatic latent image of the document (G) corresponding to the region (R1) and the region (R2) is developed with color toner and black toner, respectively. The image is transferred from the paper feed system (30) to a sheet that is conveyed to a portion facing the transfer charger (7).

The copy paper on which the toner image has been transferred is separated from the surface of the photoreceptor drum (2) by a separation belt (8), and then transported to a fixing device (41) by a transport roller (43), where the toner image is transferred to a fixing device (41). The image is fused and fixed and is discharged to a paper discharge section (42).

On the other hand, the residual toner on the surface of the photoreceptor drum (2) is removed by the cleaner device (9) and collected into the cleaner device (9), and the residual charge on the surface of the photoreceptor drum (2) is removed while the main motor is driving. The main motor (1
0) is removed.

111, timer (Tsc-A) The value of the timer (Tsc-A) will be explained.

In the copying machine (1), as shown in FIG. 9, the distances from the transfer charger (7) to the timing roller (35) and the first developing sleeve (5) are respectively (L,
), (L,), and now assume that L + > L t, when the registration switch (23) is turned on, the latent image tip (Ps') corresponding to the image tip (Ps)
) are located downstream (L, -L, .) from the opposing portion of the first developing sleeve (51) in the rotational direction of the photosensitive drum (2).

Therefore, if the distance from the leading edge of the document (Ps) on the scanning start side to the color switching point (Po) is (12), then one point (Po) of the electrostatic latent image corresponding to the color switching point (Po) is
') is located at a position CQ (LlLt)) upstream from the opposing portion of the first developing sleeve (51). Therefore, from the time when the registration switch (23) is turned on, one point (of the electrostatic latent image) corresponding to the color switching point (Po)
The time it takes for Po') to pass through the facing portion of the first developing sleeve (51), that is, the timer (Tsc-A), is as follows.

Tsc A= [12(L + Lt)
Co/VO■o: Circumferential speed of photoreceptor drum (2) In addition, specific numerical values are given as follows: L+=81xx, L*=55xx, Vo=+11x
Under the condition of x/sec, the settings are as shown in the following table.

Note that the unit of the timer (TsC-A) is (msec).

iv, Timer (Tsc-B) The timer (Tsc-B) measures the time it takes for one point on the photosensitive drum (2) to reach from the first developing device (5) to the second developing device (6), T3, developing The time it takes for one point on the sleeve (76) to reach from the ear cutting shutter (71) to the part facing the photoreceptor drum (2) is T4, and the time it takes for the ear cutting shutter (71) to change from the on state to the off state: T , based on Tsc
It is set to B-T3 T4 T5.

(2) Control The control procedure for the copying machine (1) will be explained below with reference to the attached flowchart.

1. Main Routine (See Figure 13) In the main routine, when the power is turned on and the microcomputer starts, each parameter is set in step (Ml).

In step (M2), an internal timer is started.

This internal timer has been reset in the step (Ml), and the processing time of one routine of this routine (30 m
sec), and each timer, which will be explained in the following subroutines, determines the end of the set time based on the count number of this internal timer for each routine.

Next, the subroutines of steps (M3), . . . Return to

Note that steps (M3) to (M6) are subroutines that process signals input manually from various keys on the operation panel (100), and step (M3) is a subroutine that processes input/output signals, and step ( M4) is a subroutine that processes the signal from the color selection key (121), step (M5) is a subroutine that processes the signal input from the numeric keys (+06), ~, (115), and step (
M6) is a subroutine that performs other switch processing.

Steps (Ml), ~, (M9) are the operation panel (10
This is a subroutine that controls the display of step (Ml
) is 1s2 on the display section (104) of the operation panel (100).
c. A subroutine that displays the copy mode switching point (Po) and the number of copies. Steps (~18) are a subroutine that displays the developer used according to the copy mode. Step (M9) is a toner empty display processing subroutine. be.

Steps (MIO), ~, (Ml3) are developer (5),
This is a subroutine that controls the operation of step (6).
step (Ml+) is a subroutine for switching the drive of the developing devices (5) and (6) in the 1s2c copy mode, and steps (Ml 2) and (Ml 3) is a subroutine for controlling the toner density in the developing devices (5) and (6).

Step (Ml4) is a subroutine that controls the conveyance of copy paper such as the paper feed system (30), step (Ml5) is a subroutine that controls peripheral equipment of the photoreceptor drum (2), and step (Ml6) is a subroutine that controls other devices. This is a subroutine that performs processing.

11 Detailed Description Among the above subroutines, a color selection switch processing routine [step (M4)), a numeric keypad processing routine [step (M5))], and a sheet number display section display processing routine related to operation of the operation panel (100) and display 72 will be described below. [Step (M1) L selection developing device display processing subroutine [Step (M8): l] and toner empty display processing subroutine [Step (M9)] will be described in detail in sequence.

Note that the copy mode flags (FCOLOR, F2C0LOR) and copy modes (black copy mode, color copy mode, 1
s2c copy mode) has the relationship shown in the table below, and when the power of the copying machine (1) is turned on, in the initial value setting routine (Ml) of the main routine, r'cOLOR=
0, F 2 C0LOR=O, and the black copy mode is set, which can be sequentially changed by pressing the color selection switch (121) as described below.

(See FIG. 14) The color copy selection switch processing routine is a subroutine that detects the on-edge of the color selection switch (121) and changes the values of the copy flags FCOLOR and F2C0LOR.

First, in step (SSOO) select switch (121)
Step (ss
Step (SSO2)
It is determined whether the color selection switch (121) is turned on or not, and if both are YES, the process proceeds to step (SSO3), and if any one is No, the process returns.

Next, in steps (S S O3) and (S S 04), the FCOLOR and F2C0LOR flags are set to 1 bit or “0”, respectively.
”, and step (
SS 05), (SS 20), (SS 30)
Proceed to.

Then, before the selection switch (121) is turned on, the black copy mode (FCOLOR=0, F2C0LOR
=O), step (SS30)
If the color (first) developing unit (5) is installed, PCOLOR is set to "B" in step (SS31). F2C0LOR remains at "0".

That is, in the state of black copy mode, press the selection switch (121)
When you press once, FCOLOR=ISF2COLOR=O, and the color mode is set.

Also, before the selection switch (121) is turned on, the color mode (FCOLOR=I, F2C0LOR=O
), the process proceeds to step (SS20), where it is checked whether the color developer (5) is loaded or not, and in step (SS2+) it is determined whether or not the book division mode is selected. Then, if -book split mode is not selected, proceed to step (SSO6),
Set F2C0LOR to “B”. FCOLOR is “
It remains as B.

That is, in the color mode mode, press the selection switch (12
1) Press once to set the 1s2c copy mode.

Furthermore, 1s2c copy mode (FCOLOR=1, F
If the color selection switch (+21) is turned on while the color selection switch (+21) is set to 2C0LO11=1), the step (
The process proceeds to SSO5), where it is determined whether the selection switch (121) is turned on for the first time after the copying is completed. And if it is pressed for the first time, step (SSO(i
) and set F2C0LOR=1.

That is, even if the selection switch (121) is turned on for the first time after copying in the 1s2c copy mode, the 1s2c copy mode is maintained as it is. After the 1s2c copy is completed, change the color switching point and then try 1s2 again.
This is done in consideration of the convenience of obtaining c copies.

On the other hand, after copying is complete, press the color selection switch (1) twice in a row.
21) is turned on, step (SSIO).

(SSII), set both FCOLOR and F2C0LOR to "0", and change to black copy mode.

However, after the l52c copy is completed, the color selection switch (
121) is turned on only once, the 1s2c copy mode is maintained.

In this way, in this copying machine, the selection switch (121
), the copy mode is changed in a rotational manner as shown below.

Note that if it is determined in steps (S S 20) and (S S 30) that the color developing device (5) is not installed, the process proceeds to steps (S S 10) and (S S 11) to switch to the black copy mode. is set unconditionally.

*Means the same.

b. Numeric keypad processing routine (see Figure 15) In the numeric keypad processing subroutine (step 2 M4), copy mode,
This is a subroutine that processes data input from the numeric keys (106) to (115) according to the respective modes depending on the operating state of the color selection switch (121).

First, in step (SKOO), it is determined whether the clear stop key (c/c key Xl05) is on or off, and if it is off, it is determined in step (SKOI) whether or not copying is in progress,
If copying is not in progress, proceed to step (SKO2), determine whether any of the numeric keys (105), ~, (115) is turned on, and if YES, proceed to step (SKO3)
Proceed to. Note that if the determination is No in any of steps (SKoo) to (SKO2), the process returns.

In step (SKO3), whether F2C0LOR=1 or not,
That is, it is determined whether the mode is 1s2c mode or not, and if it is the 1g2c copy mode, it is determined at step (SKO4) whether or not the color selection switch (121) is kept pressed. If the color selection switch (121) remains pressed, the input data of the switching point (Po) is permitted in step (SKO5), and the numeric keypad (10
6) Accept and accept signals input from (115).

On the other hand, when F2C0LOrt is O”, F2C0
Even if LOR=1, if the color selection switch (121) is not held down, step (SK
IO) and allow input of the number of copies. and,
In step (SKIO), it is determined whether or not it is the manual timing of the l-fold, and if YES, it is determined in step (SK11) whether the pressed key is not "0", and if it is "0", return; If it is other than "0", enter the numerical value of the key pressed with the numeric keypad in step (SK12) and return.

If it is determined in step (SKIO) that it is not the input timing for the l-fold, it is determined in step (SK20) whether or not it is the input timing for the second digit. Then, if YES, in step (SK21), the numerical value of the l-fold is moved to the 10th digit data, and further, in step (SK12), the newly input numerical value is stored as the 1st digit data.

In this way, in the numeric keypad processing routine, when the l52c copy mode is in progress and the color selection switch (12
1) is pressed, the numeric keypad (106
) to (115), the manual input of the switching point (Po) is accepted, and at other times only the number of copies can be input.

C0 number of copies display processing subroutine (see Figure 16) The number of copies display processing routine is a subroutine that displays the l52c copy switching point (Po) or number of copies on the display section 104 (104a, 104b) of the operation panel (100). It is.

First, in steps (SHOO) and (SHOl), F2
After determining whether C0LOR=1, that is, whether the 1s2c copy mode is in effect, it is determined whether the color selection switch (12+) remains pressed in the same way as before. If you are in the copy mode and the color selection switch (121) is pressed, first step (8MO2) is performed on the display section (
Display the switching point data in step 104a) and proceed to step (
SMO3) displays "P" on the display section (104b).

That is, the color switching point (Po) is displayed as "4P" and is used up.

Otherwise, step (SMI O), (SMI
l) displays the data for the 10th and 1st place in terms of number of copies, respectively. That is, if the number of copies is 25, "25'" is displayed.

d0 Selected developer display processing subroutine (see FIG. 17) The selected developer display processing subroutine is a subroutine that displays the developer selected according to the copy mode.

First, in steps (STDOO) and (STDlO), the selected copy mode is determined by detecting the value of the PCOLOR%FCOLOR flag.

Then, as shown in FIG. 10, in the case of l52c copy mode (F2COLOR=l, FCOLOR operation), the process proceeds to step (STDOII (STDO2)), and the black toner display LED (+26) and color toner display LED (1
27) are lit together.

Black copy mode (F2COLOR=0.FCOLOR=
0), steps (STD20), (STD21)
Then, the black toner display LED (126) is turned on and the color toner display LED (127) is turned off.

Color copy mode (F2COLOR=O, FCOLO
n=1), steps (STD 11), (STD
Step 12) turns off the black toner display LED (126) and turns on the color toner display LED (127).

In the above description, the operation panel (100) has a black toner display LED (126) and a color toner display LED (126).
7), but the 1st f
As shown in the figure, when the operation panel (100) is provided with a plurality of display LEDs (+50) to (154) corresponding to the toner color, the LED corresponding to the selected toner color is lit. It's okay.

e, ) empty display processing subroutine (first
(See Figure 8) The toner empty display processing subroutine
), (6) In the toner replenishment mechanism attached to
This is a subroutine that performs display processing when the toner in the toner supply bottles (81) and (91) becomes empty.

The copy mode is determined in steps (SEDOO) and (SED 10), and if it is 1s2c copy mode, first, in step (SEDOO), it is determined that the toner supply bottle (91) of the black (second) developing device (6) is in an empty state. If it is empty, the toner empty display LED (132) is turned on in step (SEDO2). On the other hand, if it is determined in step (SEDOI) that the toner has not yet decreased to the empty state, step (SEDOI)
EDll) to determine whether the toner supply bottle (81) of the color (first) developing device (5) is empty or not. If it is empty, the toner empty display LED (+32) goes to step ('l; EDO2). lights up.

That is, with the 1s2c copy mode selected,
At least one of the toner supply bottles (81), (
When the toner in 91) becomes empty, the toner empty display LED (+32) is turned on to notify the user of toner replenishment.

In the case of color copy mode, the toner supply bottle (81) of the color (first) developing device (5) is removed in step (SEDll).
) is empty or not, and if it is empty, the toner empty display LED is turned on in step (SEDO2).
(132) is lit, and if it is not empty, step (
Toner empty display LED (132) with SED12)
Turn off the light.

In case of black copy mode, black (
2nd) Determine whether or not the toner supply bottle (91) of the developing device (6) is empty, and if it is empty, step (S)
ED2+) indicates toner empty and turns on ED(132), if not, turns on LED(1) at step (SED12).
32) Turn off the light.

(Effects of the Invention) As is clear from the above description, in the image forming apparatus according to the present invention, a plurality of developing units each containing a developer of a different color are arranged on the side of the electrostatic latent image carrier. In the image forming apparatus, - toner empty display means are provided, and in an image forming mode in which a plurality of developing devices selected during one image forming operation are used, each of the selected developing devices is supplied with toner. If at least one of the toner supply tanks is empty, the empty state is displayed by the empty display means.

Therefore, even if there is no need to provide as many toner empty display means as there are developing devices, it can be selected in the case of composite copying or multicolor copying (one-shot, two-color copying) in which multiple developing devices are used during one image forming operation. If at least one of the toner replenishment tanks of the developing device is empty, the status is displayed, and the user can immediately confirm the toner empty status and replenish toner.

Therefore, it is not possible to continue forming defective images without knowing the toner empty state.

[Brief explanation of drawings]

Figure 1 is a sectional view of the copying machine, Figure 2 is a plan view of the document table, Figure 3 is a plan view of the operation panel, Figures 4 and 5 are sectional views of the developing unit, and Figure 6 is toner replenishment. A perspective view of the mechanism, FIG. 7 is a perspective view of the ear cutting mechanism, FIG. 8 is a control circuit diagram, FIG. 9 is an explanatory diagram of timer time setting, and FIGS. 10 and 11 are plan views of the main parts of the display section. 12 is a timing chart of 1-shot 2 color copying, FIG. 13 is a flowchart of the main routine, FIG. 14 is a flowchart of the color copy selection switch process, and FIG. 15 is a flowchart of the numeric keypad processing subroutine. 17 is a flowchart of the subroutine for displaying the sheet number display section, FIG. 17 is a flowchart for the subroutine for displaying the selected developing device, and FIG.
The figure is a flowchart of the toner empty display processing subroutine. 0... Optical system, l... Copying machine, 2... Photosensitive drum, 3... Charger, 4... Eraser lamp, 5... First developer (color developer), 6...Second
Developing device (black developing device), 7...transfer charger,! 1・
...Light source, 20... Original platen, 21... Original platen glass, 22... Localization value switch, 23... Registration switch, 30... Paper feeding system, 35... Timing roller, 41 ...Fixing device, 50.60...Casing,
51.61...Developing sleeve, 70...Ear cutting means,
71...Bear cutter shutter, 81°91...Toner supply bottle, 83.93...Toner empty detection sensor, 102...Print switch, 104, 104
a, IO4b-display section, 106. ~． II5...Numeric keypad, 122...Color selection switch, 126...
・Black toner display LED1127...Color toner display LEDS +32...Toner empty display LEDX
AS1, AS2...Toner concentration detection sensor, Ts
h-A...Bear cutter on delay timer, Tsh-B
...Sleeve rotation black toner removal timer, Tsh-C・
... Panicle cutting shutter off delay timer, Tsc-A: Soup solenoid switching delay timer, Tsc-B: Panicle cutting shutter on delay timer, Tsc-C: Panicle cutting shutter off timer. Patent Applicant Minolta Camera Co., Ltd. Agent Patent Attorney Aohaku Ao and 2 others Figure 2 P. Fig. 10 Fig. 1I Fig. Mouth Tip Mouth Edge Mouth Yellow Fig. 16 Fig. 17

Claims (1)

[Claims] (1) In an image forming apparatus in which a plurality of developing units each containing a developer of a different color are arranged on the side of an electrostatic latent image carrier, one toner empty display means is provided, and one image forming operation is performed. If at least one of the toner replenishing tanks that replenishes toner to the selected developing device is empty in the image forming mode using a plurality of developing devices selected in the image forming mode, the empty display means indicates that the toner is empty. An image forming apparatus characterized in that a status is displayed.