JPS6243674A - Electronic copying machine - Google Patents

Abstract

PURPOSE:To supply a proper amount of toner by controlling a toner supply means on the basis of toner consumption calculated from detected original density and original size. CONSTITUTION:The size data of an original size sensor 98 and the density data of an original density sensor 96 are inputted to a CPU 82 by operating a start key and stored in a RAM 86, and the toner consumption is calculated from the detected original size and original density. The CPU 82 supplies a signal to a motor driver 100 after said calculation to turn ON a toner supply motor 102 and a timer 88 counts a constant time required to supply a constant amount of toner; when the calculated toner consumption is larger than a constant reference value, a correction time for an increase in the amount of supplied toner is counted. Consequently, an invariably proper amount of toner is supplied and variation in toner concentration in a developing device is reduced to obtain copy images with stable density.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an electronic copying machine, and more particularly to an electronic copying machine in which toner is automatically replenished according to the amount of toner consumed.

(Prior Art) This type of electronic copying machine was released on March 11, 1985, for example.
This method is disclosed in Japanese Patent Application Laid-Open No. 60-45276 published on the same day.

This conventional technique detects the degree of the document (the area ratio of the ring portion to the white background of the document) and replenishes the amount of toner in accordance with the detection.

(Problems to be Solved by the Invention) In the above-described conventional technology, the amount of toner replenishment is controlled only based on the detected document density, and therefore, an appropriate amount of toner is not necessarily replenished.

This is because the amount of toner consumption does not depend only on the original density.

Therefore, a main object of the present invention is to provide an electronic copying machine that can always be supplied with an appropriate amount of toner.

(Means for Solving the Problems) To put it simply, the present invention calculates the consumed toner amount based on the original density detected by the original density detection means and the original size detected by the original size detection means. The electronic copying machine includes a calculation means and a toner replenishment control means for controlling the toner replenishment means based on the calculated amount of consumed toner.

(Function) The original density is detected by the original density detection means, and the original size is detected by the original size detection means. The consumption toner amount calculation means calculates the amount of toner that will be consumed when the original is copied, based on the obtained original density and original size, for example, by referring to a table or calculating according to a predetermined formula. Calculate.

Therefore, the amount of toner to be replenished depends on the document density and document size.

(Effects of the Invention) According to the present invention, since the amount of toner to be replenished is determined by the original density and the original size, it is possible to replenish a more appropriate amount of toner than the conventional method based only on the original density. I can do it. Therefore, according to the present invention, fluctuations in toner density within the developing device are reduced, and as a result, a copied image with stable density can be obtained.

The above objects, other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

(Embodiment) FIG. 2 is a structural diagram showing the internal structure of an embodiment of the present invention. Electronic copying machine 10 includes a main body 12 . Main body 12
A document table 14 is provided on the upper surface of the document plate. A paper feed section to which a paper feed cassette 16 is removably attached is formed at one end of the main body 12, and a paper discharge section including a paper discharge tray 18 is formed at the other end of the main body 12. Therefore, the original placed on the original platen 14 is recorded on the copy paper supplied from the paper feed cassette 16, and is ejected onto the paper ejection tray 18.

The document table 14 on the main body 12 is made of, for example, a transparent glass plate, and a document cover 20 is attached to the top surface of the document table 14 so as to be openable and closable. As shown in FIG. 3, this rectangular document table 14 is provided with an L-shaped document guide plate 22 spanning two sides. On this document guide plate 22, for example, from B5 to A
A display is provided indicating the vertical and horizontal sizes of up to 3 originals. Photo sensors 24a, 24b, and 24C for detecting the size of the document placed on the document cover 22 facing near the display section in the vertical direction are mounted on the document table 14.
It is provided at the position shown by the dotted line in FIG. These photosensors 24a to 24[deg.] detect the size of the original depending on whether light is reflected by the placed original.

For example, when an 84-size original is placed on the original table 14, reflected light is received by the photosensors 24b and 24a.

Note that in the case of irregular-sized originals or originals that do not reflect light from a photosensor, the original size may be detected using another method.

An operation panel 26 as shown in FIG. 4 is provided at the upper front end of the main body 12. As shown in FIG. The operation panel 26 is provided with various operation keys such as a magnification setting key 281, an image density setting key 30, and a numeric keypad 32. The copying magnification of enlargement 3 equal size or reduction set by the magnification setting key 28 is displayed on the magnification display section 40. The number of copies set using the numeric keypad 32 is displayed on the number display section 42. The image one-time setting key 30 is used to set the toner image density, that is, the density of the copied image, and the set image density is displayed in stages on the set density display section 44. The operation panel 26 is further provided with a recording paper size display section 46.

Next, the internal structure of this embodiment will be explained. In FIG. 2, approximately at the center of the interior of the main body 12 is a photosensitive drum 52 whose circumferential surface is coated with a photoconductive layer, ie, a photosensitive agent, such as amorphous silicon.
is installed rotatably in the direction of the arrow. Although not shown, a charging corotron for uniformly charging the photoreceptor drum 52 to a predetermined polarity (for example, positive polarity) is fixedly attached to the top of the photoreceptor drum 52 .

A developing device 54 for developing an electrostatic latent image (described later) with toner is provided downstream of the charging corotron near the circumferential side of the photosensitive drum 52. A photosensor 56 is provided downstream of the developing device 54 to detect the amount of toner attached to the surface of the photosensitive drum 52, that is, the density of the developed toner image.

A sensor sheet 70 provided on the document table 14 is used to detect the toner image once by the photosensor 56. That is, just before a mirror unit, which will be described later, scans a document, the sensor sheet 70 is scanned, a toner image thereof is formed on the photoreceptor drum 52, and the toner image is transmitted from the photo sensor 56 at the timing when the toner image passes the photo sensor 56. Although not shown, a transfer corotron, a separation corotron, a cleaning blade, and the like are provided downstream of the photosensor 56, which is output as a voltage signal corresponding to the image density.

A document image formed by the document placed on document table 14 is formed on the circumferential surface of photoreceptor drum 52 upstream of developing device 54 . That is, a mirror unit 62 is provided below the document table 14, and this mirror unit 62 includes an exposure light source 58 that moves while irradiating the document surface, and a mirror unit 62 that moves integrally with the exposure light source 58 to reflect light reflected from the document surface. It includes an IJ that receives light and a mirror 60. This movable mirror 6
The original image reflected by o is further reflected by a pair of movable mirrors 64a and 64b facing thereto.
The light is incident on the zoom lens 66. The mF image incident on the zoom lens 66 is formed on the surface of the photoreceptor drum 52 through a fixed mirror 65 facing the movable mirror 64b. In this way, an electrostatic latent image corresponding to the original image is formed on the photoreceptor drum 52.

A photosensor 68 is provided at approximately the same height as the zoom lens 66 to detect the density of the original. That is, by reading the density at a plurality of points on the original with this photosensor 68, it is detected as the density of the entire original.

Note that a mirror or the like may be used to focus light on the entire surface of the document onto a sensor, and the document density may be determined by integrating all inputs instead of points.

A toner hopper 7 is provided in the developing device 54 by a replenishment roller 74 rotated by a toner replenishment motor 1o2 (FIG. 5).
Toner is replenished from 6 onwards. The toner replenished by the replenishment roller 74 is stirred (mixed with carrier by the first color rough 8 and conveyed toward the photoreceptor drum 52 by the magnet roller 80. At this time, the toner of the magnet roller 80 faces the photoreceptor drum 52). A tip of the developer 72 is formed in the area, and when the tip of the tip of the tip comes into contact with the photoreceptor drum 52, negatively charged toner is attached to, for example, an electrostatic latent image formed with a positive charge. In this way, the electrostatic latent image formed on the photoreceptor drum 52 is formed as a toner image by the developing device 54 in the sheet feeding power center 16 which is detachably attached to one end side of the main body 12. Recording paper is fed in from
A toner image is transferred onto the recording paper by a transfer corotron. Thereafter, the recording paper is discharged onto the paper discharge tray 18 after completing the well-known fixing process.

FIG. 5 is a block diagram showing an example of the control system of this embodiment. The control system includes a CPU 82. The CPU 82 controls the operation of the entire electronic copying machine, calculates the amount of toner consumed, and controls the amount of toner replenishment based on the calculation. This CPU 82 includes a ROM 84 and a CPU 82 for storing control programs, etc.
A RAM 86 is connected which temporarily stores data during control and has areas for various flags necessary for control and a timer 88. Also, cpus2 has I1
A key matrix 92.0 port 90 connects a group of keys shown in FIG. A display driver 94 for driving each display section shown in FIG. 4, a document density sensor 96 including a photosensor 68, a document size sensor 98 including three photosensors 24a to 24c (FIG. 3), and a motor driver 1
00 is connected. The outputs of document density sensor 96 and document size sensor 98 are A/D converted and input to CPU 82 via I10 port 90. Based on the document density and document size, the consumed toner amount is calculated in CPtJ82. Based on this calculated amount of consumed toner,
A signal for controlling toner replenishment motor 102 is output to motor driver 100 .

Next, referring to FIG. 5, the operation of this embodiment will be described based on the flowcharts shown in FIGS. 1A and 1B. It should be noted that control related to ordinary electronic copying machines is well known, and here, control of toner replenishment will be mainly explained.

In FIG. 1A, when the start key is operated, size data from the document size sensor 98 is input to the CPU 82 and stored in the RAM 86 in the first step Sl. Next, in step S3, the document density sensor 96
The concentration data from RA is input to the CPU 82, and similarly
Stored in M86.

In the next step S5, the amount of consumed toner is calculated based on the detected document size and document density.

The amount of consumed toner is calculated based on a graph as shown in FIG. 6, for example. A graph like this is
It is stored in the ROM 84 in advance.

For example, when the original density is a predetermined value A (for example, 4%) and the original size is "A4", the standard consumed toner amount is "B".
It is determined as. When the original density increases or decreases with the same original size, the amount of consumed toner can be calculated according to the straight line indicated by "A4" in the graph in Figure 6.Also, when the original density is the same and the original size is "84" In this case, the consumed toner amount can be determined as "B+ΔBl", and when the document size is "A3", it can be determined as "B+ΔB2". In this way, in this example, the amount of toner that will be consumed at that time is calculated based on the document density and document size.

After calculating the consumed toner amount, a toner replenishment subroutine S7 is executed. In the first step S9 of the subroutine shown in FIG. 1B, the CPU 82 controls the motor driver 100.
In response, the toner replenishment motor is turned on.Then, in step S11, a timer 88 (FIG. 5) counts a certain period of time required to replenish a certain amount of toner. If the calculated toner consumption amount is greater than or equal to a certain base r7 value B (for example, the consumption toner amount when the original size is A4 and the original density is A), then
- Correction time for increasing supply amount step 513
is counted. When the timer 88 finishes counting the correction time, the CPLI 82 gives a signal to the motor driver 100 in step S15, and the toner supply motor 102 is turned off accordingly. Thereafter, the process returns to the main routine of FIG. 1A.

In step S17, it is determined whether it is continuous copying,
If it is continuous copying, the previous steps S5 and S7 are repeated. If it is not continuous copying, the copying operation is ended in the next step S19, and the electronic copying machine enters a standby state.

As described above, in this embodiment, when the consumed toner amount is above a predetermined value, the toner replenishment amount is increased, and when the consumed toner amount is below a predetermined value, a fixed amount of toner is replenished.

FIG. 7 shows a flow diagram for explaining the operation of another embodiment of the present invention. In this embodiment, when the calculated amount of consumed toner is above a predetermined value, fixed amount replenishment is performed, and when it is below a predetermined value, the amount of toner replenishment is reduced.

First, in step 5IOI of FIG. 7, the amount of consumed toner is calculated based on the detected document size and document density in the same way as steps 81 to S5 of FIG. 1A. Then, in step 5103, a copying operation is started.

In step 5105, it is determined whether the calculated toner consumption amount is less than or equal to a preset over-toner consumption amount. If the consumed toner amount is equal to or greater than the over-toner consumption amount, the toner replenishing motor 102 rotates the replenishing cam by a quarter turn in step 5107. That is, in this step 5107, a cam ON signal for a certain period of time shown in FIG. 8 is output, and the cam (not shown) is rotated by 1/4 rotation.

After that, when a certain amount of down time is counted in step 5109, the replenishment cam is set to 1/4 again in step 5111.
be rotated. Similarly, steps 5113-51
At 21, the supply cam is rotated intermittently by 1/4.

If the calculated toner consumption amount is less than or equal to the predetermined value (toner consumption 91), that is, if it is determined "YES" in step 5105, the previous steps 5107 are not executed and steps 3109 to 5121 are executed. executed. That is, the calculated amount of consumed toner is calculated in step 510.
If it is determined that the overtoner consumption amount is higher than the preset overtoner consumption amount in step 5, the replenishment cam is
If it is determined that the calculated toner consumption amount is less than or equal to the set over-toner consumption amount, the replenishment cam will rotate by 270°.In this way, as shown in FIG. As shown in , the rotation angle of the cam is varied depending on the amount of toner to be replenished.

Next, in step 5123, it is determined whether it is a continuous copy, and if it is a continuous copy, the previous steps 3105 to 5 are executed.
Repeat 121. Thereafter, in step 5125, the copying operation is completed and a standby state is entered.

Next, the operation of another embodiment of the present invention will be described based on the flowchart shown in FIG.

In this embodiment, the calculated amount of consumed toner is divided into three stages, and toner replenishment is performed in three stages accordingly.

Steps 5201 and 5203 are executed in the same manner as steps 5tot and 5103 in FIG.

In step 5205, it is determined whether the calculated amount of consumed toner is less than or equal to the overtoner value. If it is less than the overtoner value, the CPU 82 sets time data, for example "50", in the timer 88 in step 5207. If it is not less than the overtoner value, it is further determined in step 5209 whether it is equal to or more than the undertoner value. If the consumed toner amount is a value (amount) from the overtoner value to the undertoner value, the CPU 82 sets time data, for example, "100" in the timer 88 in step 3211. If it is equal to or greater than the Andattona value,
In step 5213, the CPU 82 starts the timer 88.
For example, set the time data to "150". Thus step 320? , 5211 or 3213G,
: Time data set respectively “50”, “1”
00 or “150” defines the on time of the toner supply motor 102.

In the next step 5215, a signal is given to the motor driver 100 from the CPU 82, and the toner supply motor 1 is activated accordingly.
02 is turned on. When the toner supply motor is turned on,
At step 5217, decrementing of timer 88 is started. Then, in step 5219, the photosensitive drum 5
The toner image density on 2 is detected by a toner image density sensor or photosensor 56.

Thereafter, in step 5221, the timer 88 is set to 60
”, that is, the previous step 5207,
It is determined whether the timer time set in 3211 or 5213 has been counted. If a time-up occurs, the CPU 82 performs the next step 5.
At 223, it is determined whether or not there is undertoner based on the toner image density from the photosensor 56. If there is under toner, the toner supply motor 102 is kept on for a certain period of time. Therefore, even if an error occurs in calculating the amount of consumed toner, the under-toner state is always avoided.

In the next step 5227, it is determined whether it is a continuous copy, and if it is a continuous copy, the previous steps 8215 to
Repeat 5227. Then, in step 5229, the copying operation is completed and the printer enters a standby state.

In the above embodiment, toner replenishment is carried out in three stages: below the overtoner value, between the overtoner value and the undertoner value, and over the undertoner value, but it is also possible to perform control using more stages. Probably.

Furthermore, although the amount of consumed toner is calculated by detecting the size and density of the original, the magnification of the copy image and the set toner image density (i.e., image density) may also be added to the calculation elements. . That is, when adding the copy magnification to the calculation element, the CPU 82 (FIG. 5) corrects the document size shown in FIG. . For example, if the original density is the standard value A
When the original size is 84, the increase ΔB is taken into account when the magnification is 1.0, that is, the same size copy.
If a magnification of 0.82 is set, the resulting copy will be A4, and therefore this increase ΔB1 is unnecessary. If a further magnification of 1.15 is set, the resulting copy is A3, so in this case the increase is Δ
B2 must be considered.

When considering image density, for example, if the middle level is the standard among the seven density levels, the density level is 1.
The calculated amount of consumed toner may be corrected by increasing or decreasing the amount in steps, for example by multiplying or dividing by a certain coefficient.

[Brief explanation of the drawing]

FIGS. 1A and 1B are flowcharts for explaining the operation of an embodiment of the present invention. FIG. 2 is an illustrative structural diagram for explaining the internal structure of an embodiment of the present invention. FIG. 3 is an illustrative view showing the document size sensor of this embodiment. FIG. 4 is an illustrative view showing the operation panel of this embodiment. FIG. 5 is a block diagram showing an example of the control system of this embodiment. FIG. 6 is a graph showing the relationship between the toner supply amount and the density of the document used in this embodiment. FIG. 7 is a flow diagram for explaining the operation of another embodiment of the present invention. FIG. 8 is a timing diagram showing the embodiment of FIG. FIG. 9 is a flow diagram for explaining the operation of another embodiment of the present invention. In the figure, 74 is a toner supply roller, 82 is a CPU,
84 is a ROM, 88 is a timer, 96 is a document density sensor,
Reference numeral 98 indicates a document size sensor, and reference numeral 102 indicates a toner replenishment motor. Patent Applicant Sanyo Electric Co., Ltd. Agent Patent Attorney Yama 1) Yoshito (and 1 other person) 1A-1 Figure 1B Figure 3-1 1 person Figure 4 Figure 5 Figure 6 Figure 8

Claims (1)

[Scope of Claims] 1. Original density detection means for detecting the density of the original, original size detection means for detecting the size of the original, toner replenishing means, and the original density detected by the density detection means and the original. a consumed toner amount calculating means for calculating a consumed toner amount based on the original size detected by the size detecting means; and a toner for controlling the toner replenishing means based on the consumed toner amount calculated by the consumed toner amount calculating means. An electronic copying machine equipped with a supply control means. 2. The toner replenishment control means includes means for classifying the consumed toner amount calculated by the consumed toner amount calculation means into a plurality of predetermined stages, and means for controlling the toner replenishment means according to the classification. An electronic copying machine according to scope 1. 3. The toner replenishment control means controls the toner replenishment means so as to replenish a certain amount of toner when the calculated consumed toner amount is less than a predetermined amount, and to increase the toner replenishment amount when it is greater than the predetermined amount. 3. An electronic copying machine according to claim 1 or 2, comprising means for: 4. The toner replenishment control means controls the toner replenishment means to replenish a certain amount of toner when the calculated consumed toner amount is above a predetermined amount, and to reduce the toner replenishment amount when it is below the predetermined amount. 3. An electronic copying machine according to claim 1 or 2, comprising means for: 5. The electronic device according to any one of claims 1 to 4, wherein the toner replenishment means includes a toner replenishment motor, and the toner replenishment control means includes means for controlling on-time of the toner replenishment motor. Copy machine. 6. The first aspect of the present invention further comprises means for manually setting the toner image density, and the consumed toner amount calculation means further calculates the consumed toner amount in consideration of the toner image density.
The electronic copying machine according to any one of Items 1 to 5. 7. The apparatus according to any one of claims 1 to 6, further comprising means for setting a copy magnification, and wherein the consumed toner amount calculation means further calculates the consumed toner amount in consideration of the copy magnification. electronic copy machine.