JPS61281262A - Electronic copying machine - Google Patents

Abstract

PURPOSE:To control the toner concn. without making preparations for a special detecting pattern by using the toner image of additional information to detect the toner image density. CONSTITUTION:The static latent image of additional information is formed on the photosensitive body, and it is developed by the toner. The additional information developed by the toner and transferred on the paper, namely, the density of the toner image of the additional information, is for example detected by a toner concn. detecting means 49 such as a photoelectric detecting device. In accordance with the detected toner image density, for example, the supply of the toner by a toner supplying roller 47b is controlled.

Description

[Detailed Description of the Invention] (a) Industrial Application Field This invention relates to an electronic copying machine, and in particular, forms an electrostatic latent image on a photoreceptor corresponding to an original as well as a latent image of additional information other than the original. The present invention relates to an electronic copying machine capable of printing.

(b) Conventional technology This type of electronic copying machine was developed, for example, on May 23, 1981
Japanese Patent Publication No. 58-24785 published on the date, Japanese Patent Publication No. 57-7476 published on May 11, 1988.
2, Japanese Patent Application Laid-open No. 54-92247 published on July 21, 1980, or Japanese Patent Application Laid-open No. 58-83834 published on May 19, 1988, etc.

On the other hand, Japanese Patent Application Laid-Open No. 56-78857, published on June 29, 1988, describes how to control toner density in an image forming apparatus such as an electronic copying machine that uses a two-component developer. I have fully disclosed what I will do. In this conventional toner density 5411 device, the toner density is controlled by forming a latent image of a density detection pattern on a non-transfer area on the photoreceptor and developing it in a developing section, and then detecting the density of the toner image. (c) Problems to be solved by the invention In conventional toner density control devices, a special pattern is prepared and an electrostatic latent image of the special pattern is transferred to a non-transfer area on the photoreceptor. need to be formed.

Therefore, the overall configuration becomes complicated.

Therefore, the main object of the present invention is to provide a completely new electronic copying machine that controls toner density with a simpler configuration.

(d) Means for solving the problem The present invention provides means for generating additional information other than the original, means for forming an electrostatic latent image of the additional information on a photoreceptor,
means for developing the latent image formed on the photoreceptor with toner;
An electronic copying device comprising a means for transferring a toner image onto a sheet of paper, a means for detecting the density of the toner image of additional information on the sheet, and a means for controlling the supply of toner according to the appearance of the toner concentration detecting means. It is a machine.

(e) An electrostatic latent image of additional information is formed on the working photoreceptor and developed with toner. The density of the additional information completely transferred to the toner-developed paper, that is, the density of the toner image of the additional information, is detected by a toner density detection means such as a photoelectric detector.

Depending on the detected toner image density, the supply of toner by, for example, a toner supply roller is controlled.

(f) Examples FIG. 1 is an overall external view showing one embodiment of the present invention.

The electronic copying machine 10 includes a main body 12, and a document table 14 is provided on the upper surface of the main body 12. The document table 14 is supported so as to be movable left and right. A paper feed section into which a paper cassette 16 is removably inserted is formed, 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 paper supplied from the paper feed cassette 16, and the paper is ejected onto the paper ejection tray 18.

An operation panel 20 is also formed on the upper surface of the main body 12, and this operation panel 20 is provided with a numeric keypad 22, a group of selection keys 24, and a start key 26. Numeric keypad 2
2 can be used, for example, to set the number of copies, and a group of selection keys 24 can be used to select images other than the original image, that is, additional information or secondary information, such as date, company name, telephone number, etc. Ru. The start key 26 is
Used to command copy start.

The operation panel 20 further includes L as an example of a display device.
CD (Liquid Crystal Displ
ay) A panel 28 is formed, and this LCD panel 28 displays the desired number of copies and information selected with the selection key group 24, as will be explained in detail later with reference to FIG. A seven segment indicator is included to indicate the type by number.

Here, with reference to FIG. 2, the internal structure of the embodiment shown in FIG. 1 will be explained in detail. As described above, the document table 14 is provided on the top surface of the copying machine main body 12 so as to be movable in the left-right direction. The document table 14 is made of, for example, a transparent glass plate, and a document cover 30 is attached to the top surface of the document table 14 so that it can be opened and closed.The document table 14 is made of, for example, a transparent glass plate. A photosensitive drum 32 coated with a photoconductive layer, ie, a photosensitive material, is installed so as to be rotatable in the direction of the arrow (clockwise). A short focus lens array 3 is mounted on the top of the photoreceptor drum 32.
4 is fixedly attached so that its optical axis points substantially vertically. The short focal length lens array 34 forms an original image formed by the original placed on the original platen 14 on the circumferential surface of the photosensitive drum 32 . Above this short focus lens array 34, as will be described in detail later, there is a monolithic structure that emits light as a second light source for forming an electrostatic latent image of additional information other than the original image on the photoreceptor drum 32. A guide array (LED array) 36 is provided.

Further, a charging corotron 38 for uniformly charging the photoreceptor drum 32 to a predetermined polarity (for example, positive polarity) is fixedly attached to the upstream side of the short focus lens array 34 in the rotational direction of the photoreceptor drum 32. . An exposure lamp 40 made of, for example, a halogen lamp is provided above the charging corotron 38 to expose the surface of the document placed on the document table 14. In front of this exposure lamp, for example, a filter 4 for absorbing infrared rays is provided.
2 is provided.

An electrostatic latent image of the original is formed in most of the area on the photosensitive drum 32 by the corotron strip 38, the exposure lamp 40, the short focus lens array 34, and the original placed on the original platen 14. Further, the LED array 36 forms an electrostatic latent image other than the original image, that is, an electrostatic latent image of additional information, in a part of the area on the photoreceptor drum 32 .

Short focus lens array 3 near the circumferential side of the photoreceptor drum 32
A developing device 44 for developing the electrostatic latent image as described above with toner is provided downstream of the image forming apparatus 4 . A mixture of toner and carrier (developer) 46 is stored in the developing device 44 , and the developer 46 is conveyed toward the photosensitive drum 32 by a magnet roller 48 . At this time, a spike of the developer 46 is formed on the portion of the magnet roller 48 facing the photosensitive drum 32, and when the tip of this formation comes into contact with the photosensitive drum 32, an electrostatic charge formed by, for example, a positive charge is generated. For example, negatively charged toner is attached to the latent image. In this way, the photosensitive drum 32 is
The electrostatic latent image formed thereon is formed as a toner image.

Note that the blade 50 included in the developing device 44 is used to control the height of the spikes of the developer 46 .

Copy sheets 52 are stored in a stacked manner in a paper feed cassette 16 that is removably attached to one end of the main body 12.

At the bottom of this paper feed cassette 16, a copy paper 52 is provided.
A support plate 54 on which is placed is provided so as to be swingable in the vertical direction. An opening 56 is formed below the support plate 54, and a free end of a push-up lever 58, whose base end is swingably attached to the inner bottom of the main body 12, is inserted through the opening 56. A spring (not shown) is provided in association with the push-up lever 58 to bias the lever 58 clockwise, and the support plate 54 is pushed upward by the spring. Therefore, the copy sheets 52 stacked in the paper feed cassette 16 are pushed up by the push-up lever 58, and the uppermost copy sheet 52 is
The paper contacts the paper feed roller 60 and is taken in.

A register roller 62 is provided behind the paper feed roller 60, and this register roller 62 allows the paper feed cassette 1 to be
The copy paper 52 fed from the copy paper 6 stops once, and then is fed in the direction of the photosensitive drum 32 in synchronization with the movement of the document table 14. Note that a photosensor 64 provided near the register roller 62 is used to detect whether copy paper 52 is present in that area.

A developing device 4 is located near the side surface of the photoreceptor drum 32 to which the copy paper 52 is supplied from the register roller 62.
A transfer flotron 66 is provided for transferring the toner image developed by 4 onto copy paper 52. A separation corotron 68 is provided integrally with the transfer flotron 66, and the separation corotron 68 is used to transfer the copy paper 52 onto which the toner image formed on the photoreceptor drum 32 is transferred to the photoreceptor drum 32. In order to prevent the copy paper 52 from being attracted by residual charges thereon, alternating current corona discharge is applied to the copy paper 52 after transfer to neutralize the charges.

A vacuum conveyor 70 is provided downstream of the separating flotron 68 for conveying the copy paper 52 onto which the toner image has been transferred. This vacuum conveyor 70
As a result, the copy paper 52 is conveyed toward the fixing device 72 .

Further, as will be described in detail later with reference to FIG. 15, a toner image density detector 4 is provided above the vacuum conveyor 70.
9 is provided. This toner image density detector 49 is
It is used to detect the toner density of the toner image on the copy paper 52 corresponding to the portion of the electrostatic latent image of additional information formed by the D array 36.

The fixing device 72 includes a pressure roller 78 that is pressed against a heat roller 76 that has a built-in heater 74 . Then, the copy paper 52 with the toner image transferred thereto is
By being inserted between the two rollers 76 and 78, the fixing process is performed by heating and pressurizing the rollers 76 and 78.
- The claw 8° provided in relation to the rough 6 is used to prevent the copy paper 52 after fixing from being offset to the heat roller 76. A paper discharge row 282 is provided downstream of the heat roller 76 for discharging the fixed copy paper 52 onto the paper discharge tray 18 (FIG. 1). A detection switch 84 is provided on the downstream side of the paper discharge roller 82 to detect whether copy paper 52 is present there.

A cleaning device 86 is provided above the vacuum conveyor 7o and near the circumferential side of the photoconductor drum 32, and the cleaning device 86 removes toner remaining on the photoconductor drum 32 without being completely transferred. do. This cleaning device 86 includes a cleaning blade 88 for scraping off the residual toner, and a waste toner container 9o which stores the toner scraped off by the cleaning blade 88.
A screw conveyor 92 is included for conveying.

In order to control the overall operation of such a copying machine, a control box 94 is provided, and this control box 94 houses various components necessary for a control system as shown in FIG. 10, which will be described later. There is.

Referring to FIG. 3, the display panel 28 has a numeric display section 29 for displaying the number of copies set using the numeric keypad 22 (FIG. 1), and a selection key group 24 (FIG. 1). These two display sections 29 and 31 both include a number display section 31 for displaying a number representing the type of additional information, and a 0 number display section 31 that includes a 7-segment display.
includes a plurality (five in this embodiment) of 7-segment displays, and therefore, in this embodiment, it is possible to simultaneously record a combination of a plurality of types of additional information in addition to the original image. When, for example, a key 243 is pressed after a key 24a of a group of selection keys 24, which will be described later, is pressed,
'3° on the 7 segment display key at the left end of the number display section 31
' will be displayed, and the numbers of the keys that have been successfully operated will be sequentially displayed on this display.

Note that the display panel 28 includes these display sections 29 and 3.
In addition to 1, display characters representing paper sizes required for ordinary electronic copying machines are formed.

The selection key group 24 includes a plurality of keys (11 keys in this embodiment) as shown in FIG. 4, and the first key 24m is used to record additional information or sub information using the selection key group 24. The first key 24b is used to command
is used to indicate that the operation for selecting the type of additional information has been completed. For example, nine selection keys 241 to 249 are provided to display nine types of information. Note that the above-mentioned key 24a may be used as a command means for toner density control.

The key 241 is used, for example, to instruct whether to record additional information in English or Japanese, and when this key 241 is pressed, the additional information in English is displayed. Become. The key 242 is used, for example, to identify whether the additional information is recorded in the horizontal or vertical direction of the copying machine, and when this key 242 is operated, the additional information is formed in the vertical direction. And key 243
is used, for example, to record the word "5ECRET" indicating the necessity of confidentiality as additional information. For example, the key 244 is the date, the key 245 is the company name, the key 246 is the name of each department in the company, the key 247 is the company address, the key 248 is the telephone number, and the key 249 is the slogan. , are used for selection as additional information. Various slogans can be considered as additional information. Note that the types of additional information are merely examples, and any additional information may be set as necessary. For example, when the key 24m is pressed, the information for toner density control is set accordingly. An image may be formed, and the additional information corresponding to these keys 243 to 249 is as follows.
The DRAM 144, which will be explained later with reference to FIG. 10, stores the data in advance as a digital code corresponding to each number.

Here, the operation or operation of the electronic copying machine of this embodiment will be briefly explained. Operate the desired selection key included in the selection key group 24 on the operation panel 20 (FIG. 1), place the original on the original platen 14, and then press the start key 26 to start exposing the original. A scan is performed. That is,
The document table 14 once moves to the left end, then moves to the right,
During this movement to the right, the original is subjected to slit exposure by the light source 40. The reflected light from the original, that is, the original image, is projected onto the photoreceptor drum 32 by the short focal length lens array 34, and thereby the photoreceptor drum j2
A first electrostatic latent image corresponding to the original image is formed thereon. At this time, the LED array 36 selectively emits light according to the content corresponding to the operated one of the selection keys 24, such as the date, and the light image from the LED array 36 is exposed to light through the short focus lens array 34. the second on the body drum 32
is formed as an electrostatic latent image.

The first electrostatic latent image and the second electrostatic latent image completely formed in this way are both developed with toner by the developing device 44.

Such a toner image is transferred onto the copy paper 52 fed through the register roller 62 by the action of a transfer Flotron 660. The copy paper 52 on which the toner image has been transferred is separated from the photosensitive drum 32 by a separating corotron 68, and transferred to a fixing device 72 by a vacuum conveyor 70.
sent to. Then, the transferred toner image is fixed onto the copy paper 52 by the heat roller 76 and the pressure roller 78, and then the copy paper 52 is discharged onto the paper discharge tray 1B by the paper discharge roller 82.

Note that the density of the toner image of the additional information is detected from the toner image on the copy paper 52 moving below the toner image density detector 49 by the vacuum conveyor 70. That is,
The toner image of the additional information is also used as a pattern for toner image density detection.

Then, the toner remaining without being completely transferred to the copy paper 52 is
The cleaning device 86 removes residual toner from the photoreceptor drum 32, and the photoreceptor drum 32 is then newly charged by the charging corotron 38.

Here, with reference to FIGS. 5 to 9, short focus lens array 34. Details of the LED array 36 and the like will be explained. The short focus lens array 34 includes a plurality of rod lenses arranged in a direction perpendicular to the rotational direction of the photoreceptor drum 32, that is, across the entire axial width of the photoreceptor drum 32. A parallel-extending lead screw 96 is rotatably attached to body 12 . This rounded screw 96 is screwed into and inserted into a screw hole formed through the holder 98. Therefore, this holder 98 is supported by a lead screw 96 on the short focus lens array 34 so as to straddle it. The output shaft of a stepping motor 100 is connected to one end of the lead screw 96, and when the stepping motor 100 is energized, the lead screw 96 rotates, and the holder 98 is connected to the shaft of the fixed screw 96. It can be moved or displaced in parallel in the direction of the arrow. Accordingly, the LED array 36 mounted on this holder 98 can also be displaced in the direction of the arrow. Note that the exposure lens 40 is arranged to extend parallel to the short focus lens array 34.

A cross-sectional view of the LED array 36 and the short focus lens array 34 taken in a direction perpendicular to the axis of the photoreceptor drum 32 is shown in FIG. However, in this FIG. 6, the holder 98 (FIG. 5) is omitted. L.E.
The D array 36 is fixed to an alumina substrate 102, and this alumina substrate 102 is fixed to a fixed base 104. The fixing base 104 is made of a metal material with good thermal conductivity, such as aluminum, and also functions as a radiation fin. This fixing base 104 is fixed to a holder 98 (FIG. 5).

As can be clearly seen from FIG. 8, an LED array 36 is sandwiched between the alumina substrate 102 and the LED array 36.
LED driver 10 consisting of an integrated circuit for driving
6 is attached. This LED driver 106 is connected to a connector 108 mounted on the alumina substrate 102, and a flat cable 110 is connected to the connector 108. Therefore, this flat cable 110 (FIGS. 7 and 8) and the cable 108
The LED driver 106 receives the LED from the control unit via the LED driver 106.
A lighting drive signal for the D array 36 is given. Note that a transparent glass plate 112 is attached to the lower part of the fixed base 104,
In addition, the LED array 36 and the like are protected.

A partially enlarged plan view of LED array 36 is shown in FIG. The LED array 36 is configured as a monolithic structure and includes a large number of light emitting parts 114 arranged in a row, and an electrode 116 is formed in association with each of the light emitting parts 114. , the alumina substrate 1 via the bonding wire 118
02 (FIG. 8). Each light emitting section 11 in this LED array 36
The size of the array 36 is, for example, 0.07 x 0.08 ml, the entire length of the array 36 is, for example, 14.84 m, and the arrangement pitch of the light emitting parts 114 is, for example, 0.106 ff.
It is ll. The number of light emitting parts, ie, the number of dots, of this LED array 36 is, for example, m128''.

The above c7) LED7 ray 36 is made of, for example, GaAsP.
(7) It is composed of a group of red LED elements formed by mounting GaAS on the base x, and its emission wavelength is about 660 nm. On the other hand, as the exposure lamp 4o for irradiating the document surface, a light source that emits visible light, such as a halogen lamp or a fluorescent lamp, can be used. In this example a halogen lamp is used.

The center wavelength of a halogen lamp is approximately 500 nm - 1,000 nm.
nm, and in some species it is around 550 nm. Therefore, for the photosensitive drum 32, it is necessary to select a photoconductive material having a photosensitive peak wavelength that is effectively sensitive to both of these two wavelengths. However, L
Since the light from the ED array 36 is weaker than the light from the exposure lamp 40, it is especially important to use LEDs as the photosensitive drum 32.
It is necessary to choose a material that is sensitive to light from array 36. For this purpose, in this embodiment, the photosensitive drum 32
The photosensitive peak wavelength of is selected, for example, from 600 to 700 nm.

Materials for the photoconductive layer of the photosensitive drum 32 having such a photosensitive peak wavelength include amorphous silicon, OP
C% 5e-Te, AS2863 and CdS are available. In particular, amorphous silicon is suitable as a material for the photosensitive drum 32 because it not only has such photosensitive properties but also excellent mechanical properties such as good abrasion resistance.

In FIG. 6, "Tc" is the conjugate length, "Zo" is the length of the short focus lens array 34, and "Lo" is the distance from the end surface of the lens array 34 to the LED array 36 or photosensitive drum 32. each represents. These conjugate length Tc and lens length Z.

is related to the respective emission wavelengths of the exposure lamp 40 as the first light source and the LED array 36 as the second light source. This relationship is shown in the table below.

T c (mm) Z o (mm) Wavelength (nm
) Exposure lamp 70.3 28.5 560
LED array 16.7 8.5 660 As can be seen from this table, the red LED array 36 and the halogen lamp 40 have different emission wavelengths, so the length of the lens used must be changed. Therefore, in this case However, if green LEDs are used as the LED array 36, the emission center wavelength will be approximately 560 nm.
m, it is approximately equal to a halogen lamp, and therefore, in this case, the short focus lens array 34 of the same size
can be used.

FIG. 10 is a block diagram showing an example of the control system of this embodiment. The control system includes an 8-pit C, such as the μPD8085AC/D-2 manufactured by NEC.
PU13G is included. This CPU 13G controls the overall operation of the electronic copying machine, the recording of additional information, and the supply of toner. This CPU 130 includes a ROM 1 for storing control programs to be described later.
32 and a RAM 134 that temporarily stores data during control by the CPU 13G and has areas for various flags and counters necessary for control. As the ROM 132, for example, μPD2764D manufactured by NEC can be used, and as the RAM 134, μPD8155HC manufactured by NEC can be used.

In order to compensate for the lack of I10 port of CPU 130,
Programmable input/output interface (PIO) 1
36 is provided, and the PIO 136 of B acts as an input/output port for the copy mechanism section controlled by the cpU 130 and the ROM 132.
8, all control mechanisms related to the operation of the electronic copying machine are integrated.

The above-mentioned components, along with the CPU 13G and other components, are connected by a bus 14G, which includes an address bus, a data bus, and a controller bus.

A DMAC (direct memory access controller) 142 is connected to the bus 14G, and the DMA C14
2 is a dynamic RAM without the mediation of the CPU 13G.
The contents stored in (DRAM) 144 are selected and provided directly to character generator 146. character generator 1
46 is composed of, for example, an EFROM, and a DRAM 14
Based on the character code representing the information or content sent from 4, a 32x32 dot LED drive signal is generated and applied to the LED driver 106 (FIG. 8). Therefore, the LED constituting the light source for additional information
Array 36 includes character generator 146 or DRA
Depending on the content of M144, a plurality of light emitting units 114 (FIG. 9) are selectively driven to form the necessary character.

In addition, as the DMA C142, for example, NEC
-PD8257C/D-2 manufactured by NEC Corporation, and as the character generator 146, for example, μPD2764D manufactured by NEC Corporation.
can be used.

A key matrix 148 is coupled to bus 140 via PIO 150. This PI0150 is the previous PIO
Similar to 136! It has 10 ports. The keys described above with reference to FIGS. 1 and 4 can be connected to the key matrix 148. Therefore, this key matrix 148 not only contains operation keys for the electronic copying machine but also stores additional information. Receives operation signals from a group of keys for selection, and outputs key food signals corresponding to each of them.
Provided to CPU130 through IO15G.

The DRAM 144 temporarily stores key food representing the type of additional information selected by the selection key group 24 (FIG. 4). The key food is stored as 8-bit data. Specifically, for example, when the selection key 246 (fourth @) is operated, the key food representing that key 246 is stored in the DRAM 144;
4, the additional information corresponding to the key 246 '5AN
XX ELECTRICCO,,LTD" is output. This character code selects the address of the character generator 146, and the character generator 146 sequentially outputs the characters ""5-A-N. -X-X...The LED drive signal (32X 32 dots) is transmitted to the LED driver 10 according to the
6 d is given. Therefore, in this embodiment, the DRAM 144 includes a conversion unit that can sequentially output the codes of characters constituting the additional information based on a single number keychain representing the type of additional information.

Note that the character generator 146 sequentially outputs 32×32 dot drive signals one column at a time, and therefore, one character is formed by the LED array 36 only after the drive signals have been output for 32 columns from the LED driver 106. be.

The LCD driver 152 is for driving an LCD panel 28 as shown in FIG. 3, for example. In addition,
As such an LCD panel 28, a dot matrix type may be used instead of a segment type.

In addition, U A RT (IJ universal 5y
nchronous/Asynchronous/Re
The receiver/transmitter 154 acts as a serial-to-parallel conversion defuder for exchanging signals with the outside, and is, for example, a μPD8251A made by N2O.
FC/D is available.

Next, referring to FIG. 10, the operation of this embodiment will be described based on the flowchart shown in FIG. 11. In addition,
The control related to the operation of a normal electronic copying machine is well known, and here, the control for recording additional information will be mainly explained.

In the first step S1, the CPU 130 selects the DRAM
144 is cleared to 0. Then, in step S3, CP
The U 130 looks at the signal from the PIO 150 and determines whether there is an input from the key matrix 148, that is, a key input. Then, if there is key power, in the next step S5, select keys 241 to 249 (FIG. 4)
The key hood corresponding to the operated key is displayed on CPU1.
Load into A register in 3G. And step S
At step 7, the CPU 130 transfers the contents of the A register, that is, the key food corresponding to the selected key, to the DRA.
Transfer to M144. Therefore, in the next step S9, the DRAM 144 outputs the code of each character forming the additional information corresponding to the operated selection key.

In step Sll, the key code, that is, the number of the details of the additional information is displayed on the number display section 3 of the LCD panel 28.
1 (Figure 3).

When it is detected in the next step S13 that the start key 26 has been operated, the CPU 130 sets the timing necessary for copy start in the copy mechanism section 138 in step S15, and also sets the additional information. Set the recording start position, that is, the timing.

In the next step 517, when it is determined based on the set time that the position or timing for recording the additional information has come, in the following step 819, the CPU 130 initializes the DMA C 142. Then, in the next step S21, the DRAM 14
The start address and number of transfer bytes for DMA from 4 to the character generator 146 are set.

In the next step 823, the DMA operation is started, and as described above, the LED array 36 is driven and one additional information selected by the keys 241 to 249 is recorded (steps 825 to 31). ), and the LED drive signals of all characters of additional information are output,
Step S indicates that recording of all characters has been completed.
If the determination is made in step 33, then in step 835 the CPU 130 determines whether the operation related to the copying operation as an electronic copying machine has been completed, and if so, this processing routine is terminated.

Note that prior to this determination of termination, a toner image density detection subroutine shown in FIG. 16, which will be described later, may be executed.
This subroutine will be explained in detail later.

The operation for recording additional information as described above will be explained in more detail with reference to the example shown in FIG. now,
As shown in FIG. 12(A), first, the start key 24a of the selection key group 24 is pressed, then the selection keys 241, 243, 246, 249 and 244 are operated in sequence, and finally the end key is pressed. 24b shall not be operated. When the key operations are performed in this order, the number display section 31 of the LCD panel 28 will display al, 3 fists 6, 9, 4.
” is displayed on the notebook paper 52, as shown in Fig. 12 (
B), the respective keys 241.243.2
Information corresponding to 46.249 and 244 is recorded in English.

As mentioned above, when recording additional information together with the original image on the same copy paper, as shown in FIG.
A holder 98 for the array 36 is positioned at the axial end of the photoreceptor drum 32, thereby preventing an electrostatic latent image of the document from being projected onto the area where the additional information is to be recorded. be done. This is to clearly record the additional information in the corresponding area. To explain in more detail, in the state shown in FIG.
Since the additional information on 2 is in the information of the area to be formed, the original image is not projected onto that part. A latent image and an electrostatic latent image of additional information will be formed. When the electrostatic latent image of such additional information is developed with toner, it is also used as a pattern for detecting toner image density.

As explained above, any information can be recorded in the form of the additional information, but in order to detect the toner image density, the so-called "black It is preferable to have a solid part, and such a 1 black solid part is generated by the character generator 146 (
From Figure 10, for example, all $2 x 32 dots are '1
It can be formed by outputting a character food that looks like this.

Further, in order to form an image of "1 white solid" for the reference density, it is sufficient to generate a character hood of all "0" from the character generator 146.

Next, the developing device 44 will be explained in more detail with reference to FIG. The developing device 44 includes a developer box 45a and a toner box 45b formed above the developer box 45a.

A developer 46 is stored in the developer box 45g, and toner is stored in the toner box 45b. A stirring rod 47a is provided inside the toner box 45b to stir the toner 46a stored therein in order to prevent the toner from solidifying. toner box 45
An opening that communicates with the developer box 45a is formed at the bottom of b, and a toner supply roller 47 is formed in the opening.
b is provided. This toner supplying roller 47b is made of a material such as urethane sponge, and when rotated in the direction of the arrow by a motor (not shown), the toner supplying roller 47b receives toner 46 from the toner box 45b. , a are supplied in the developer box 45a. A stirring roller 51 is provided in the developer box 45a to promote mixing of the toner 46a and the carrier and to negatively charge the toner.

Then, the toner and carrier are thoroughly mixed in the developer/shiba box 45a, and the toner is developed onto the surface of the photoreceptor drum 32 by the magnetic roller 48 with a magnetic brush. A constant bias voltage is applied to this magnet row 248, which determines the threshold for toner development onto the drum.

Next, the toner image density detector 49 will be described in detail with reference to FIG. A toner image density detector 49 is provided above the vacuum conveyor 70. Photosensitive drum 32
includes a holder 98 (see FIG. 2) containing the LED array 36 (FIG. 2).
The electrostatic latent image of the additional information formed by the process shown in FIG. 5) is developed by the developing device 44 to form a toner image of the additional information. This toner image is then transferred to a transfer Flotron 66
(FIG. 2), the image is transferred onto copy paper 52. The toner image of this additional information includes a black image portion 158, a self-portrait portion 160,
and the desired additional information described above. The above-mentioned toner image density detector 49 is provided facing the toner image of this additional information.

Note that the black image area 158 and the white image area 160 as shown in FIG. 15 are automatically turned on, for example, when the start key 248 (FIG. 4) for forming additional information is operated. , such a pattern may be generated from the character generator 146.

The toner image density detector 49 includes a light emitting element 4 such as an LED for irradiating light onto a toner image area of additional information.
A drive signal from the light emitting driver 162 is applied to the light emitting element 49a, which includes a light receiving element 49b such as a phototransistor, which receives light reflected from the toner image forming area of the additional information. Light receiving element 49b
The output of
Drive command signal from P U 13G is given, A/D
Digital data from converter 166 is input to CPU 130 through the bus. In this example, the description will be given assuming that the CPU 13G shown in FIG. 10 also controls toner density control, but another control means such as a microprocessor may be used for this purpose.

A subroutine for controlling toner density will be described in detail with reference to FIG. 16.

In the first step 841, when development by the developing device 44 is started, after a certain delay time ensured in step 843, the CPU 130 executes the next step 8.
At 45, the light emitting driver 162 is connected through the bus 140.
Give a light emission drive command to. Accordingly, the light emitting driver 162
However, the light emitting element 49a included in the toner image density detector 49
to drive. Then, light from the light emitting element 49a is irradiated onto the toner image forming area of the additional information, reflected therefrom, and received by the light receiving element 49b. For example, a voltage signal having a magnitude corresponding to the toner image density from the light receiving element 49b is amplified by the amplifier 164 and then input to the A/D converter 166. The A/D converter 166 outputs digital data representing the magnitude of the input voltage signal, that is, the density of the toner image of the additional information. and,
In step 847, the CPU 130 takes in data from the A/D converter 166 through the bus.In step S49, the CPU 130 takes in the data from the A/D converter 166 through the bus.
At step 47, the imported digital data is compared with reference data. As the reference data in this step 349, previously set data may be used, but
In this embodiment, digital data of the level of the white image portion 160 shown in FIG. 15 is used.

Then, in step 851, the CPU 130 compares the toner image data of the black image area 158 with the data of the self-portrait area 160 among the toner images of the additional information, and determines whether the difference is greater than a predetermined certain level. to judge. If the difference is not greater than a certain value, the toner concentration is insufficient, so in step 853, the CPU 130 issues a command to a motor (not shown) through the bus to drive the toner supply roller 47b. Accordingly, a certain amount of toner 4ta is delivered from the toner box 45b (FIG. 14).
It is supplied to the developer box 45a. therefore,
The toner density in the developer box 45a is increased. After that, 'YES' in the previous step S51.
The process returns to the main routine in the same way as if it had been determined that this is the case.

This subroutine as shown in the 16th @ may be executed every time a copy operation is performed, or may be executed every time the number of copy operations is minus.

(G) Effects of the Invention According to the present invention, the toner image with additional information can also be used for toner image density detection, so there is no need to prepare a special detection pattern, and it is more efficient than conventional methods. The toner concentration can be controlled with a simple structure.

[Brief explanation of drawings]

FIG. 1 is an external view showing an embodiment of the present invention. FIG. 2 is a structural diagram for explaining the internal structure of the first embodiment. FIG. 3 is an illustrative view showing an example of a display panel. FIG. 4 is an illustrative diagram showing an example of the arrangement of a group of selection keys for selecting the type of additional information. FIG. 5 is a perspective view of main parts showing a short focus lens array and an LED array. FIG. 6 is a lateral cross-sectional view showing a short focus lens array and an LED array. FIG. 7 is a partially cutaway perspective view showing the short focus lens array and the LED array. FIG. 8 is a perspective view showing an LED array and an alumina substrate on which it is formed. FIG. 9 is a partially enlarged plan view showing the LED array. FIG. 10 is a block diagram showing an example of the control system of this embodiment. FIG. 11 is a flowchart for explaining operations or operations for forming additional information in this embodiment. FIG. 12 is a diagram showing an example of additional information formed by this embodiment. FIGS. 13(A) and 13(B) are diagrams showing other examples of additional information, respectively. 14 is a partially enlarged sectional view showing the developing device in detail. No. 15vlJ is a schematic block diagram showing a main part of an embodiment of the present invention. FIG. 16 is a flow diagram for explaining the operation of the embodiment shown in FIG. In the figure, 32 is a photosensitive drum, 44 is a developing device, 4
9 is a toner image density detector; 47b is a toner supply roller;
130 indicates a CPU.

Claims (1)

[Scope of Claims] 1 Additional information generating means for electrically generating additional information other than the original image; means for forming a latent image of the additional information on a photoconductor; and a latent image formed on the photoconductor. means for developing the image with toner; means for transferring the developed toner image onto supplied paper; toner image density detection means for detecting the density of the toner image transferred to the paper; An electronic copying machine comprising a toner control means for controlling toner supply according to the output of a toner image density detection means. 2. The electronic copying machine according to claim 1, wherein the toner image density detection means includes comparison means for comparing the density of the toner image of the additional information transferred onto the paper with a reference density. 3. The electronic copying machine according to claim 2, wherein the additional information generating means generates black image information as the additional information. 4. The electronic copying machine according to claim 3, wherein the additional information generating means generates white image information that should be the reference density as the additional information. 5. The electronic copying machine according to any one of claims 1 to 4, wherein the density detection means includes a photoelectric detector facing a position on the sheet where a toner image is formed. 6. The electronic copying machine according to claim 5, wherein the photoelectric detector includes an LED and a light receiving element for receiving reflected light from the LED reflected by the paper. 7. The electronic copying machine according to any one of claims 1 to 6, wherein the means for forming an electrostatic latent image for the additional information includes an LED array.