JP2521935B2 - Erase device for copier - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an erase apparatus which is disposed near a photosensitive drum of a copying machine and which exposes and removes (or reduces) a charge on a predetermined portion of the drum surface. Regarding improvement.

[Prior Art] In a copying machine of an electrophotographic process, an erasing device is generally arranged near the surface of a photosensitive drum. this is,
This is to prevent the toner from adhering to the unnecessary portion by exposing and removing the charge on the unnecessary portion (development unnecessary portion) before the development of the electrostatic latent image.

Initially, the unnecessary portion was supposed only in the peripheral portion of the copy sheet, but there is a strong demand to secure a non-development area inside the copy area such as erase, trimming, or synthetic copy. An erase device is provided in which a large number of LED elements are arranged in the axial direction of a photoconductor drum and the light emission of the large number of LED elements is individually controlled to secure a non-developing area inside the copying area. Has arrived.

Further, in recent years, when copying a document, there is a demand that not only the document image but also simple character or number data such as date data be copied.

As a method of coping with this, it is possible to electro-optically write a desired character shape on the surface of the photoconductor drum by using the erase device and individually controlling ON / OFF of the LED elements constituting the erase device. It is considered.

[Problems to be Solved by the Invention] In the above description, the required accuracy is different between the case of removing the charge in a predetermined region such as erase and trimming and the case of removing the charge in the character shape.

FIG. 11 is a diagram for explaining the problems of the conventional erase device.

As shown in the figure, conventionally, the tip of the erase device and the surface of the photoconductor are placed about 3 mm apart. This is to reduce the local fluctuation of the potential on the surface of the photoconductor due to the spatial variation of the intensity of the light that illuminates the photoconductor surface, by using the influence from the LED light sources adjacent to each other. belongs to.

However, as described above, the surface of the photoconductor and the tip portion are
When the distance is about 3 mm, the unevenness of the irradiation light intensity is reduced, but the sharpness of the boundary between the charge-removed region and the non-removed region is impaired. For this reason, when characters are written using the erase device as described above, the sharpness of the characters to be written is impaired.

The present invention has been devised in view of such circumstances, and it is possible to electro-optically and accurately write sharp characters on the surface of the photoconductor drum, and at the time of editing and copying such as erasing and trimming, the above-mentioned place It is intended to provide an erasing device free from potential fluctuation (ripple).

[Means for Solving Problems] According to the present invention, a lens array is interposed between the LED light source and the photoconductor drum at the time of writing the characters to prevent diffusion of a light beam and thus secure the sharpness. It is a thing.

That is, the present invention relates to an erasing apparatus for a copying machine, which is disposed near the surface of the photoconductor drum and between the charging charger and the developing device, and exposes and lowers the potential of a predetermined portion of the surface of the photoconductor drum. In the exposure light emitting portion of the erase device, a large number of LED elements capable of individually controlling light emission are arranged in the axial direction of the photoconductor, and the LED emitting light from the exposure light emitting portion is used.
A lens array for preventing light diffusion, the lens array having a first position for preventing the LED light diffusion, and the LED
An erasing device for a copying machine, comprising: a moving unit that moves the light to and from a second position that does not prevent diffusion of light.

In the present invention, the light emitting portion for exposure has a width in the axial direction of a light output portion of a continuous LED element of a large number of LED elements in the axial direction of a light output portion of another LED element. It is an eraser for a copying machine, which is smaller than the width of

Further, the present invention is the erase apparatus for a copying machine, wherein the first position is in the optical path of the LED light and the second position is outside the optical path of the LED light.

 A supplementary explanation will be given below.

(1) Device Location The present invention is installed near the surface of the photoconductor drum and between the charging charger and the phenomenon device. The charging charger gives a uniform charge to the surface of the photosensitive drum.
Note that the electric charge flows out at a portion where image exposure or LED light irradiation is performed.

(2) LED (light emitting diode) element The material and the like may be the same as the conventional one. The drive circuit only needs to be capable of individually driving each LED element in accordance with a signal from the control means.

(3) Lens array Any lens array can be used as long as it can prevent the diffusion of LED light. For example, a SELFOC lens array in which a large number of optical fibers are bundled can be used.

(4) Moving means According to a predetermined control signal, the lens array is placed in the optical path of the LED light at a position different from the first position for preventing diffusion of the LED light and the first position. Anything can be used as long as it can be moved to and from a certain second position. The control signal is transferred from, for example, the control CPU of the edit input device.

[Operation] Normally, a lens array is not interposed between the light emitting portion and the surface of the photoconductor, and functions as an erasing, trimming, edit copying such as composite copying, or an inter-image erasing device.

When inputting characters, the lens array is moved to the first position by the moving means to prevent the diffusion of the LED light.

This prevents a local ripple at the time of editing and copying and secures the sharpness of the boundary portion at the time of writing characters.

The static elimination function is performed electro-optically. That is, the charging of the photoconductor is removed by the irradiation of light from the LED element, and the toner development in that portion becomes impossible.

[Embodiment] An erase device according to an embodiment and a method of using the same will be described below.

{Description of Erase Device} FIG. 1 shows an eraser (erase device) according to this embodiment.
4 is a perspective view of FIG. 4, and FIG. 2 is a schematic cross-sectional view showing the positional relationship of the eraser 4 with respect to the photosensitive drum 61.

As shown in the figure, the eraser 4 of this embodiment has 34 LED elements each having the same width (5 mm bitch; 41 a in the figure) of the light output portion as the conventional one, and the narrow width (1 mm pitch) of the light output portion. 41b in the figure) a light output section 41b having 47 LED elements and having a small width is arranged at the right end of the figure, while a light output section 41a having a large width is provided.
Are arranged at the center and on the left end side. It should be noted that the LED elements are not shown in the figure because they are arranged behind the light output section.

Further, a drive circuit shown in FIG. 4 which will be described later is housed in the case 42, and the circuit is connected to a CPU for controlling the eraser and a power source through a line.

A SELFOC lens array (trade name) 400 is arranged in front of the narrow LED element 41b. The lens array 400 is formed by bundling a large number of optical fibers, and as will be described later, the light passing through the lens array is parallel light.

The lens array 400 is attached to a plate 415 connected to the frame 800 via pins 417 protruding from the body frame 800,
They are connected by a letter-shaped portion 418 and are rotatable about the pin 417 as shown by an arrow a.

The plate 415 is coupled to a pin 411 protruding from the frame 800 via a spring 416, and is biased upward by the spring 416, whereby the lens array 400
Are usually located above the case 42. Also, the plate 41
A solenoid 413 is arranged below the element 5, and a shaft 414 of the solenoid is connected to a plate 415. That is, when the solenoid 413 is energized, the plate 415 is electrically attracted and rotates downward as described above.

The configuration of the present invention is not limited to the above, and for example, instead of the solenoid, a stepping motor or the like may be used to drive the lens array.

Entering characters with the eraser 4, or editing and copying,
It is realized as follows.

As shown in Fig. 3, 34 LEDs with a wide optical output width
By imagining the symbols a1 to a34 from the left to the elements and turning on the LED elements Ca to Da from the end time of the timer XA to the end time of the timer XB and irradiating the surface of the photosensitive drum 61, the drums
The electrostatic charge in the area corresponding to the perspective portion of the drawing of 61 is removed.
Therefore, no toner adheres to the area during the developing process, and therefore the area corresponding to the area on the copy sheet becomes blank.

On the other hand, when writing characters, 47 LEDs with a small light output width are used.
By selectively turning on and off the elements b1 to b47,
This can be realized by removing the charge on the surface of the photoconductor drum 61 to, for example, a shape of “23” (actually, its reflected image shape). For the on / off control of the LED element, for example, a font pattern as shown in FIG. 8 is stored in a memory, and the font pattern is read by a predetermined key input or the like to create a bitmap. , A signal from the bitmap can be used. Note that FIG. 8 is a diagram showing a part of the font pattern written in the memory, and each font has a 5 × 7 dot configuration. That is, in the above description, the reason why the number of LED elements having a small light output axis is set to 47 is that eight characters each having a 5-dot axis can be arranged. Therefore, as the number of characters or the number of dots forming a character increases or decreases, the number of LED elements also appropriately increases or decreases.

{Explanation of Eraser Drive Circuit} FIG. 4 shows a drive control circuit of the eraser 4.

As shown, the drive control circuit is a shift register 401,
It has a latch 402 and a driver 403, which are controlled by a signal transferred from the eraser control CPU 22 to control ON / OFF of each of the drive transistors Tr (1) to Tr (81).

Further, each LED element (LED (1) to LED (81)) is driven by the power supply voltage Vcc.

{Description of Editor 900} FIG. 5 is a perspective view of the editor 900 connected to the copying machine. In the present embodiment, the editor 900 is placed on the original table 8 of the copying machine as shown in FIG. 7 described later.

As shown, the editor 900 has a tablet 910 and a key
901-905.

The tablet 910 has a large number of resistance wires 911 arranged at intervals of about 1 mm in the X-axis direction and the Y-axis direction, respectively. The resistance value determined by the Y coordinate is detected at the voltage level. Therefore, when it is desired to input a specific point of the document as X and Y coordinate data, the document is restricted and placed on the tablet 910 and the specific point is pressed.

Characters corresponding to the font shown in FIG. 8 “A, B, C, ... Y, Z, or 1, 2, 3, ...” are written on the tablet (not shown), A desired character can be selected in association with a character key 903 described later.

The keys 901 to 905 are an erase key, a trimming ski, a character key, an end key, and a clear key in this order. The erase key is a key for designating a full erase within a specific area, and the trimming key is a key for designating a full erase outside a specific area. The character key is a key for specifying a character input mode, and the end key is a key for ending the input of coordinates or characters. The clear key is a key for canceling the above designation.

{Explanation of lens array} FIGS. 6 (a) and 6 (b) are explanatory views of the path of LED light. FIG. 6 (a) shows the case without a lens array, and FIG. 6 (b) shows the case with a lens array. .

As shown in FIG. 6A, the photosensitive drum 61 and the eraser 4
If there is no lens array between the LED light source 41 and the light source, the light emitted from the LED light source 41 diffuses (after being regulated by the partition wall 410 separating the LED light sources 41) and reaches the surface of the photosensitive drum 61. as a result,
At the boundary, the lights from the adjacent LED light sources 41 are overlapped with each other, and the local fluctuation of the potential is alleviated.

On the contrary, when there is a lens array between the photoconductor drum 61 and the eraser 4, as shown in FIG.
The light emitted from the lens array 400 is collimated by the lens array 400 (after being regulated by the partition wall 410 separating the LED light sources 41) and reaches the surface of the photosensitive drum 61. As a result, sharp characters can be written without overlapping the lights from the LED light sources 41 adjacent to each other at the boundary.

{Description of Copying Machine Main Body} Next, the configuration of a copying machine equipped with the eraser of the above-described embodiment will be described.

As shown in FIG. 7, a copying machine equipped with the eraser of this embodiment has an optical system 5 for exposing and scanning an original to transmit an image.
(51 to 55), an image forming unit 6 (61 to 69) for reproducing the transmitted image on a copy sheet by an electrophotographic process, and a paper feeding / discharging system for supplying the copy sheet and fixing the image. 7 (71-76)
And a platen 8 made of glass.

(A) Optical system The optical system 5 includes a light source (not shown), mirrors 51, 52, 53,
54, a lens 55, and a drive mechanism (not shown), which reciprocates along the lower surface of the document table 8 and exposes and scans the document surface during forward movement. That is, the reflected light from the document is reflected by the mirrors 51, 52,
After being reflected by 53, the lens (lens block for zooming) 55
Further, the light is reflected by the mirror 54, reaches the photosensitive drum 61, and forms an image on the surface of the drum 61. Mirrors 51, 52, 53
Are driven by the same exposure scanning motor M3. The moving speed is v / n (n; copying magnification) for the mirror 51 with respect to the weekly speed v of the photosensitive drum 61, and the mirrors 52 and 53 keep v / 2n for keeping the optical path length constant. Is. On the other hand, the mirror 54 and the lens 55 are driven in conjunction with each other by the magnification setting motor M4. Here, the lens 55 moves on the optical axis to change the copy magnification, and the mirror 54 moves and swings to correct the image formation point.

(B) Image forming unit 6 The image forming unit 6 is a photosensitive drum that can be rotationally driven in the arrow direction.
61, a main eraser lamp 62 disposed around the drum 61, a sub-charger 63, and a sub-eraser lamp 6
4. It has a main charging charger 65, a developing device 66, a transfer charger 67, a copying paper separation charger 68, and a blade type cleaning device 69.

The eraser 4 of the present embodiment is disposed between the main charger 65 and the developing device 66 and in proximity to the photoconductor drum 61. The position of the eraser 4 is closer to the main charger 65 than the image exposure in this case, but it may be closer to the developing device 66. In other words, it suffices that the position is after the uniform charging by the charging charger 65 and before the development by the developing device 66.

A photoconductor layer is formed on the surface of the drum 61, and the photoconductor layer is sensitized and charged by passing through the eraser lamps 62 and 64 and the chargers 63 and 65. An electrostatic latent increase is formed upon exposure to slit (image) exposure.

Toner is attached to the formed electrostatic latent image in the developing device 66, and the attached toner is transferred to the transfer charger 67.
At, the image is transferred onto a copy sheet (supplied through the timing roller 73 of the sheet feeding / discharging system 7).

(C) Paper feeding / discharging system 7 The paper feeding / discharging system 7 includes a paper upper cassette 71 and a paper lower cassette 72,
Sending roller pairs 711 and 721, conveying roller pairs 712 and 713, timing roller pair 73, conveying belt 74 of each cassette,
The fixing device 75, the discharge roller pair 76, and the like are driven by the main motor M1.

The toner image transferred onto the paper is heat-fixed between the rollers of the fixing device 75.

{Operation | movement operation | movement} Below, operation | movement of the apparatus of a present Example is demonstrated.

FIG. 9 No. 1 and No. 2 are controlled by the CPU 22 (editor 9
00 and control of the eraser 4). Note that control of copying operation, temperature adjustment, and the like is publicly known, so description thereof will be omitted.

As illustrated, the CPU 22 starts the process by turning on the power, for example, and first sets an initial state (S102). For example, the value m of the counter that counts the number of times the font pattern is read from the font memory is set to 0, and the value n of the counter that counts the number of times of coordinate designation is set to 0. Also, each flag is turned off and each memory is cleared. After that, a routine timer that defines the time for one routine is set (S104).

 Next, in S106, the input / output is activated.

Next, in S108, the coordinate is specified by the end flag,
Also, it is determined whether the reading of the font pattern has been completed.

If the end flag is not set in S108, that is, if the input of the coordinate data and / or the reading of the font pattern is not completed, the processes of S112 to S146 are executed.

In S112, first, it is determined whether or not a coordinate signal is input from the tablet 910. This is determined based on whether or not there is a change in data input from the tablet 910 via an A / D converter (not shown).

If it is determined in S112 that "there is input", the process proceeds to S114 on the condition that the character mode is not present, that is, "W flag = 0" (S113), and n (coordinate input count) It is determined whether or not the value has reached 2. If not, the process proceeds to S116, where the input (x, y) coordinate signal is stored in the memory, and then the value of n is incremented by 1 (S118). ), And then returns to S104. In the present embodiment, when the area is specified, since it is specified as a rectangular area, it is sufficient to specify two pieces of coordinate data (points at both ends of the diagonal line), so the upper limit value of n is set to 2.

If “W flag = 1” in S113, the character mode is set, and the process proceeds to S132.

In S132, it is determined whether or not the value of m (the number of read-outs of the font pattern) has reached 8, and if not, S1
Proceeding to 36, the font pattern (see FIG. 8) corresponding to the character written in the portion pressed by the light pen 950 (FIG. 5) is read from the font memory (S136), and the eraser 4 is turned on- Create a bitmap to control the OFF in the bitmap memory (S13
8). After that, the value of m is incremented by 1 in S140, and then the process returns to S104. The upper limit value 8 of m is determined by the number of LED elements 47 of 1 mm pitch of the eraser 4 and the number of horizontal dots 5 of one character.

If "No input" is determined in the determination in S112,
Proceed to S120 and later.

In S120, it is determined whether the erase key 901 has been input,
E flag (erase flag) when "input"
Set up (S122) and return to S104. If there is no input, S1
Proceed to 24.

In S124, it is determined whether or not the trimming key 902 has been input, and if "input is present", a T flag (trimming flag) is set (S126), and the process returns to S104. In the case of “input dream”, the process proceeds to S128.

In S128, it is determined whether or not the character mode key 903 has been input, and if "input is present", a W flag (character mode flag) is set (S130), and then the process returns to S104. In the case of "no input", the process proceeds from S128 to S142.

In S142, it is determined whether or not the end key 904 is input,
If "input" is specified, input coordinate data and /
Alternatively, it is determined that the conversion from the coordinate data to the character data is completed, the end flag is set (S144), and the process returns to S104.
In the case of "no input", the process proceeds from S142 to S146.

In S146, it is determined whether or not the clear key 905 has been input.
If "input is present", the process returns to S102, and if "input is not present", the process returns to S104.

As described above (S112 to S146), coordinate data and /
Alternatively, character data (bitmap) is stored in the bitmap memory.

When it is determined in S108 that the end flag is set, that is, when the coordinate data and / or the character data (bitmap) is stored in the bitmap memory,
In step S110, it is determined whether the copying machine is in the copying operation.

 If the copy operation is in progress, the process proceeds to S150 and thereafter.

S150 to S158 are steps for performing erase control on the designated area. That is, from y = y ₁ to y = y ₂ , from x _{1 to} x ₂
By turning on the LED element, (x ₁ , y ₁ ), (x ₂ , y ₂ )
The inside of a rectangular area with the vertex of the diagonal line is full erased.

On the other hand, S162 to S174 are steps for trimming the designated area. That is, from y = y ₁ to y = y ₂ , x ₁ ~
By turning off the LED element of x ₂ , (x ₁ , y ₁ ), (x ₂ , y
₂ ) Erases outside the rectangular area with the diagonal apex.

S176 to S184 follow the bitmap corresponding to the font pattern stored in the memory, and from the time when y = y ₁ is reached, the LED elements (LED (35) to LED (8
In this step, 1)) is individually controlled to be turned on and off to remove the charge on the photoconductor 61 in a predetermined character pattern. That is, on condition that the W flag = 1 (S176), the pressure contact solenoid 413 (see FIG. 1) is turned on (S177) to interpose the lens array 400 between the erase device 4 and the photosensitive drum 61. , Turn off the exposure lamp (S178), prepare for writing characters, and after reaching the image tip y ₁ (S180),
Based on the bit map table created in 38, each LED element of the eraser is turned on and off (S182), characters are written electro-optically, and then the crimp solenoid 413 is turned off (S
184), the lens array 400 is retracted from between the erase device 4 and the photosensitive drum 61, and returned to the original position.

In this way, the character pattern is sharply written on the copy paper.

FIGS. 10 (a) and 10 (b) show copy samples with and without the lens array.

As shown in the figure, when the lens array is used (b),
The boundary is sharp.

On the other hand, when it is not used (a), the boundary becomes a blurred image.

〔effect〕

As described above in detail, according to the present invention, in the eraser device for a copying machine in which a large number of LED elements are arranged, when inputting characters, the lens array is moved to the first position by the moving means to prevent the diffusion of the LED light. However, the sharpness of the character boundary is ensured.

On the other hand, at the time of editing and copying such as erasing and trimming, the lens array is retracted to the second position by the moving means, so that the ripple caused by the nonuniformity of the removed charges is prevented.

[Brief description of drawings]

FIG. 1 is a perspective view of an eraser according to an embodiment. Second
The figure is a perspective view for explaining the positional relationship between the eraser and the photosensitive drum. FIG. 3 is an explanatory view for explaining a character entry method by the eraser. FIG. 4 is a drive circuit diagram of the eraser. FIG. 5 is a perspective view of the edit input device. FIG. 6 is an explanatory diagram of the function of the lens array. FIG. 7 is a diagram showing the construction of a copying machine equipped with an eraser. FIG. 8 is an explanatory diagram of font patterns. Figure 9 Part 1 and 2
3 is a flowchart showing control of the CPU. FIG. 10 is a copy image diagram of a case where the lens array is not used and a case where the lens array is used. FIG. 11 is an explanatory diagram of the relationship between the distance between the surface of the photoconductor and the tip of the eraser and the irradiation light intensity. 4 ... Erase device, 416 ... Spring 413 ... Solenoid

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location G03G 15/36

Claims (3)

(57) [Claims] 1. An erasing device for a copying machine, which is disposed in the vicinity of the surface of a photosensitive drum and between a charging charger and a developing device, and exposes and reduces the potential of a predetermined portion of the surface of the photosensitive drum. The exposure light emitting unit of the erase device is formed by arranging a large number of LED elements capable of individually controlling light emission in the axial direction of the photoconductor to prevent diffusion of LED light emitted from the exposure light emitting unit. And a moving means for moving the lens array between a first position that prevents diffusion of the LED light and a second position that does not prevent diffusion of the LED light. Erase device for copiers characterized by: 2. The exposure light emitting unit according to claim 1, wherein a width in the axial direction of a light output unit of a continuous LED device among a large number of LED devices is large. , Other L
An erasing device for a copying machine, characterized in that it is smaller than the width of the light output part of the ED element in the axial direction. 3. The device according to claim 1, wherein the first position is in the optical path of the LED light, and the second position is the second position.
Is located outside the optical path of the LED light. Erase device for copying machine.