JPS63165882A - Eraser for copying machine - Google Patents

Abstract

PURPOSE:To make the border part of entered characters sharp and to prevent the generation of rippling by arranging a lens array between an exposing light emitting part and the surface of a photosensitive drum. CONSTITUTION:The lens array 400 is arranged between the LED element 41b and the photosensitive drum 61. The array 400 is coupled with a plate 414 by an L-shaped part 418 through a pin 417 plated into a body frame 800 and constituted so as to be rotated around the pin 417 as shown in an arrow (a). Since the array 400 is arranged between the element 41 and the drum 61 and LED light is prevented from being diffused, the border part of entered characters is made sharp at the time of entering characters or the like. In case of editing copying such as erasing and trimming, the array 400 is removed, so that rippling due to the positional unevenness of removed charge can be suppressed.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an erase device that is placed near a photoreceptor drum of a copying machine and that removes (or reduces) the charge on a predetermined portion of the drum surface by exposing it to light. Regarding improvements.

[Conventional Technique #I] In a copying machine using an electrophotographic process, an erase device is generally arranged near the surface of a photoreceptor drum. This is quiet! ! i This is to expose and remove the electrical charge in unnecessary areas (areas that do not require development) before developing the latent image, and to prevent toner from adhering to the unnecessary areas.

Initially, the unnecessary parts were only assumed to be the periphery of the copy paper, but it could be erased, trimmed, composited, etc.
As the demand for securing an acyclic (IEI) area inside the copying area has become stronger, in recent years a large number of LED elements have been arranged in the axial direction of the photoreceptor drum, and the light emission of the large number of LED elements has been individually controlled. death.

An erase device capable of securing a non-development area inside the copy tI4 area has now been provided.

Furthermore, in recent years, when copying a document, there is a desire to copy not only the document image but also simple character or numerical data such as date data.

As a method to deal with this, using the above erase device,
It has been considered to electro-optically write a desired character shape on the surface of a photoreceptor drum by individually controlling on/off of the ED elements that constitute the erase device.

[Problem to be Solved by the Invention 1] In the above, the accuracy required is different depending on whether the charge is removed from a predetermined area such as erasing or trimming, and when the charge is removed from a character shape.

FIG. 11 is a diagram illustrating problems with the conventional erase device.

As shown in the figure, conventionally, the tip of the erase device and the surface of the photoreceptor are spaced apart from each other by about 3+n.

This is to reduce local fluctuations in the potential of the photoreceptor surface due to local variations in the intensity of the light irradiating the photoreceptor surface by utilizing the influence from adjacent LED light sources. belongs to.

However, as mentioned above, the surface of the photoreceptor and the tip are
If the distance is about mm, the non-uniformity of the intensity of the irradiated light is reduced, but the sharpness of the boundary between the charge removal area 1 and the non-charge removal area is impaired. For this reason, if an attempt is made to write characters using the eraser as described above, the sharpness of the written characters will be impaired.

The present invention has been devised in view of the above circumstances, and is capable of electro-optically inscribing sharp characters with high precision on the surface of the photoreceptor drum. The present invention provides an erase device free from potential fluctuations (ripples).

[Means for Solving the Problems] The present invention interposes a lens array between the LED light source and the photoreceptor drum when writing the above-mentioned characters, thereby preventing the diffusion of the light beam and thereby ensuring the sharpness. It is something.

That is, the present invention provides an erase device for a copying machine, which is disposed between a charger near the surface of a photoreceptor drum and a developing device, and lowers the potential of a predetermined portion of the surface of the photoreceptor drum by exposing it to light, the erase device comprising: The light emitting unit for exposure of the device individually emits light wtm.
a lens array that includes a large number of LED elements arranged in the axial direction of the photoreceptor drum, and that prevents diffusion of light emitted from the LED elements; An erase device for a copying machine is characterized in that it has a drive means interposed between the erase device and the drive means.

A supplementary explanation is given below.

(1) Installation Location This device is installed near the surface of the photoreceptor drum, between the charger and the developing device. The charger applies a uniform charge to the surface of the photoreceptor drum. Note that the charge flows out at a portion exposed to image exposure or irradiated with ED light.

(2) LED (light emitting diode) element materials may be the same as conventional ones. The drive circuit may be of any type as long as it can drive each LED element individually according to a signal from the control means.

(3) Lens array Any material may be used as long as it can prevent diffusion beyond the LED.

For example, a SELFOC lens array in which a large number of optical fibers are bundled can be used.

(4) Driving means Any device may be used as long as it can move the lens array so as to be interposed between the light emitting section for exposure and the surface of the photoreceptor drum in accordance with a predetermined control signal. The control signal is transferred, for example, from the CPU of the editing input.

[Function] Normally, a lens array is not interposed between the light emitting section and the surface of the photoreceptor, and the device functions for editing copying such as erasing, trimming, and composite copying, or as an inter-III erase device.

When writing characters, a lens array is placed between the surface of the photoreceptor and the light emitting section for exposure according to a control signal, and the LE
D Diffusion of light is prevented.

This prevents local ripples during editing and copying, and ensures the sharpness of the boundary portion when writing characters.

Note that the static elimination function is performed electro-optically.

That is, irradiation of light from the LED element removes the charge on the photoreceptor, making it impossible to develop toner in that area.

[Example] Hereinafter, an erase device according to an example and a method of using the same will be explained.

(Description of erase device) Figure 1 shows the eraser (erase 'aM>) according to this embodiment.
4, and FIG. 2 is a schematic cross-sectional view showing the position a 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 of 5+e-pinch 2 (41a in the figure), which has the same width as the conventional light output part, and has a small width of the light output part (11a).
I111 pitch; 4l in the figure b) It has 47 LED elements, and the small width light output section 41b is arranged at the right end side in the figure, while the large width light output section 41a is arranged at the center and left end side. has been done. Note 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 this circuit is connected to a CPU for controlling the eraser and a power source via 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 made into parallel light.

The lens array 400 is connected to a plate 415 connected to the frame 800 via a pin 417 protruding from the main body frame 800 at a single-shaped portion 418.
It is rotatable about 7 as shown by arrow a.

The plate 415 is coupled to a pin 411 protruding from the frame 800 via a spring 416, and is urged upward by the spring 416, so that the lens array 400 is normally placed above the case 42. positioned. Further, a solenoid 413 is arranged below the plate 415, and a shaft 414 of the solenoid is connected to the plate 415. That is, when the solenoid 413 is energized,
The plate 415 is configured to be electrically attracted and rotate downward as described above.

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

Writing of characters or editing and copying by the eraser 4 is realized as follows.

As shown in Figure 3, 34 LEs with large optical output width
Dl! Assuming codes a1 to a34 from the left to the child, if the LED element of [)a to Ca is turned on from the end time of timer XA to the end time of timer XB to illuminate the surface of the photosensitive drum 61, the drum The electrical charge in the area corresponding to the shaded area in the diagram 61 is removed. Therefore, toner does not adhere to this area during the development process, and therefore, the area corresponding to the area on the copy paper becomes blank.

On the other hand, the writing of characters is done using 47 LEs with a small width of the optical output section.
By selectively turning on and off the D elements b1 to b47, the charge on the surface of the photoreceptor drum 61 can be reduced to, for example, "23".
It can be realized by removing it into the shape (actually, the shape of its reflected image).

The on-off control of the LED elements can be carried out by, for example, storing a font pattern as shown in FIG. This can be done by signals from the bitmap. FIG. 8 is a diagram showing a part of the font patterns stored in the memory, and each font has a 5×7 dot configuration. That is, in the above, the number of LED elements with a small light output width is 47.
The reason for this is to make it possible to line up 8 characters of 5 dots horizontally. Therefore, as the number of characters or the number of character dots increases or decreases, the number of LED elements also increases or decreases as appropriate.
.

(Description of eraser drive circuit) FIG. 4 is a drive control circuit diagram of the eraser 4.

As shown in the figure, the drive illll 1111 circuit includes a shift register 401, a latch 402, and a driver 403, which are controlled by a signal transferred from the CPU 22 for eraser control, and are connected to each drive transistor Tr.
(1) Controls on/off of ~Tr (81).

In addition, 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 editor 900 connected to a copying machine. In this embodiment, the editor 900 is placed on the document table 8 of the copying machine as shown in FIG. 7, which will be described later.

As illustrated, the editor 900 includes a tablet 910,
keys 901 to 905.

The tablet 910 has a large number of resistance wires 911 arranged at approximately 1 ms intervals in each of the X-axis direction and the Y-axis direction,
By pressing any point on the tablet to short circuit,
The resistance value determined by the X and Y coordinates of the arbitrary point is detected as a voltage level. Therefore, when it is desired to input a specific point on a document as X and Y coordinate data, it is sufficient to place the document on the tablet 910 and press the specific point.

Also on the tablet are rA, B, C,...Y12,
Or, ``1.2.3, etc.'' are filled in with characters corresponding to the font shown in Figure 8 (not shown), and the desired character can be selected in association with a character key 903, which will be described later. It looks like this.

Keys 901 to 905 are, in order, an erase key, a trimming key, a character key, an end key, and a clear key. The erase key is a key that specifies full erase within a specific area, and the trimming key is a key that specifies full erase outside the specific area.

Also, the character key is a key that specifies the character input mode,
The end key is a key that ends input of coordinates or characters. The clear key is a key for canceling the above designation.

(Explanation of lens array) Figures 6 (a) and (b) are explanatory diagrams of the path of LED light, where (a) shows the case without a lens array, and (b) shows the case with a lens array, respectively. .

As shown in FIG. 6(a), the photosensitive drum 61 and the eraser 4
If there is no lens array between the
(after being defined by W1), the light is diffused and reaches the surface of the photoreceptor drum 61. As a result, at the boundary, adjacent LED light sources 41
The light from the two overlaps, and local fluctuations in potential are alleviated.

On the other hand, when there is a lens array between the photosensitive drum 61 and the eraser 4 as shown in FIG. 6(b), the light emitted from the LED light sources 41 is
IR1I for 10! After being subjected to II), the light is made into parallel light by the lens array 400 and reaches the surface of the photoreceptor drum 61. As a result, the lights from adjacent LED light sources 41 do not overlap at the boundary, making it possible to write characters sharply.

(Description of the copying machine main body) Next, the configuration of the copying machine equipped with the eraser of the above embodiment will be explained.

As shown in FIG. 7, the copying machine equipped with the eraser of this embodiment has an optical system 5 (5
1 to 55), and an image forming unit 6 (61 to 69) that reproduces the transmitted image on copy paper by an electrophotographic process;
A paper feed/discharge system 7 (7) feeds copy paper and fixes images.
1 to 76) and a glass document table 8.

(a) Optical system The optical system 5 includes a light source (not shown) and mirrors 51, 52, 5.
3.54, a lens 55, and a drive mechanism (not shown), it moves back and forth along the lower surface of the document table 8, and exposes and scans the document surface during forward movement. That is, the re-splitting light from the original is reflected by mirrors 51, 52, 53, passes through a lens (variable lens block) 55, is further reflected by a mirror 54, reaches the photosensitive drum 61, and is transferred to the photosensitive drum 61. 61 surface. The mirrors 51, 52, and 53 are driven in conjunction with the same exposure scanning motor M3. Its movement speed is
With respect to the peripheral speed ■ of the photoreceptor drum 61, the mirror 51 is v/
n (n; copying magnification), and the mirror 52.5
3 is v/2n in order to keep the optical path length constant. On the other hand, the mirror 54 and the lens 55 are operated by a magnification setting motor M4.
It is driven in conjunction with. Here, the lens 55 moves on the optical axis to change the copying magnification, and the mirror 54 moves and swings to correct the image point.

(b) Image forming section 6 The image forming section 6 includes a photosensitive drum 6 that can be rotated in the direction of the arrow.
1, a main eraser lamp 62 disposed around the drum 61, a sub charger 63, a sub eraser lamp 64, a main charger 65, a developing device 66,
Transfer charger 67, copy paper separation charger 68,
It has a blade type cleaning 1it69.

The eraser 4 of this embodiment has a main charger 65 and a current f! The photoreceptor drum 61 is disposed between the photoreceptor drum 61 and the photoreceptor drum 61 . In this case, the position of the eraser 4 is closer to the main charger 65 than the image exposure position, but it may be located closer to the current Illustrator 66.

In other words, the position may be any position after uniform charging by the charger 65 and before development by the developing device ff166.

A photoreceptor layer is formed on the surface of the drum 61, and the photoreceptor layer is sensitized and charged by passing through the eraser lamp 62.64 and the charger 63.65, and the photoreceptor layer is sensitized by passing through the eraser lamp 62, 64 and the charger 63, 65. An electrostatic latent image is formed upon 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 6.
7, copy paper (timing roller 7 of paper feed/discharge system 7)
(supplied via 3).

(C) Paper supply and discharge system 7 The paper supply and discharge system 7 consists of a paper upper cassette 71 and a lower paper cassette 72.
, a pair of delivery rollers 711.721 for each cassette,
Conveyance roller pair 712,713, timing roller pair 73
, a conveyor belt 74, a fixing device 75, a pair of discharge rollers 76, etc., and these are driven by a main motor M1.

Note that the toner image transferred to the paper is
is thermally fixed between rollers.

(Operation explanation) The operation of the apparatus of this embodiment will be explained below.

9, parts 1 and 2 are flowcharts showing the control of the CPU 22 (IIJIII of the editor 900 and the eraser 4). Note that controls such as the copying operation and temperature adjustment are well known, so explanations thereof will be omitted.

As shown in the figure, the CPU 22 starts processing, for example, by turning on the power, and first sets an initial state (8102). For example, the value m of a counter that counts the number of times a font pattern is read from the font memory is set to O, and the value (Illn) of a counter that counts the number of coordinate designations is set to O, respectively.

Also, each flag is set down and each memory is cleared.

Thereafter, a routine timer that defines the time for one routine is set (8104).

The process then proceeds to 8106 to activate input/output.

Next, in step 8108, it is determined based on the end flag whether or not the designation of coordinates and the reading of the font pattern have all been completed.

If the end flag is not set in 8108, that is, if input of coordinate data and/or reading of font pattern is not completed, processes in 5112 to 5146 are executed.

At 5112, first, it is determined whether or not an external target 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 5112 that there is an input, the process proceeds to 5114 on the condition that it is not in character mode, that is, on the condition that it is "W flag - ○" (8113), and n(
Determine whether the value of (number of coordinate inputs) reaches 2,
If not, proceed to 8116, store the input (x, y) coordinate signal in memory, and then set the value of n to 1.
Increment 8118), and then return to 5104. Note that in this embodiment, when specifying an area, it is specified as a rectangular area, so the upper limit value of n is set to 2 because it is sufficient to specify the coordinate data with two points at both ends of a diagonal line.

If it is "W flag - 1" in step 5113, it is the character mode, so the process advances to step 5132.

At 5132, it is determined whether or not the value of m (the number of font pattern reads) has reached 8. If it has not reached 8, the process advances to 5136 and is written in the area pressed by the light pen 950 (FIG. 5). Read the font pattern (see Figure 8) corresponding to the character being displayed from the font memory (8136) and turn on/off the eraser 4.
A bitmap for till is created on the bitmap memory (3138). Then at 5140 m
After incrementing the value by 1, the process returns to step 5104.

The upper limit value of m, 8, is determined by the number of LED elements of the eraser 4, 47, with a pitch of 1111 m, and the number of horizontal dots, 5, of one character.

If the determination in step 5112 is that it is in the "input state", the process proceeds to step 5120 and subsequent steps.

At 5120, it is determined whether or not the erase key 901 has been input, and if it is determined as "input cloth", an E flag (erase flag) is set (8122), and the process returns to 8104. "Input state"
If so, proceed to 5124.

In 5124, it is determined whether there is an input to the trimming key 902, and if it is determined as "input cloth", a T flag (trimming flag) is set (8126), and the process returns to 5104. In the case of "input state", the process advances to 8128.

At 8128, it is determined whether there is an input from the character mode key 903, and if it is determined as "input cloth", the W flag (character mode flag) is set (8130), and then the process returns to 5104. "
In the case of "input state", the process advances from 5128 to 5142.

In step 5142, it is determined whether there is an input on the end key 904, and if it is determined as "input cloth", an end flag is set as that input of coordinate data and/or conversion from coordinate data to character data has been completed. (8144), 8104
Return to In the case of "input state", the process proceeds from 5142 to 5146.

At 8146, it is determined whether the clear key 905 has been input. If it is an "input cloth", the process returns to 5102, and if it is an "input state", the process returns to 5104.

As described above (8112-8146), coordinate data and/or character data (bitmap) are stored in the bitmap memory.

If it is determined that the end flag is set at $108, that is, if the coordinate data and/or character data (pitmap) are stored in the bitmap memory, the process advances to 8110, and the copying machine is in the copying operation. Determine whether or not.

If a copy operation is in progress, the process advances to 5150 and subsequent steps.

8150-8158 are steps for controlling the erase of the designated area. That is, from V-V+ to y-yt, XI to X! By lighting up the LED element of (X
i*V'), (xt, Vt) is a rectangular area with vertices of the diagonal line being fully erased.

On the other hand, steps 5162 to 5174 are steps for trimming the specified area. That is, from y-yl to V-/!
By turning off the LED elements XI to X2 until
(X+, V+), (Xt.

The area outside the rectangular area whose diagonal vertices are yx) is erased.

8176 to 8184 are V −' according to the bitmap corresponding to the font pattern stored in memory.
/ From the time when + is reached, the LED element of eraser 4 (L
This is a step of individually controlling on/off of the ED (35) to LED (81)) to remove the charge on the photoreceptor 61 in a predetermined character pattern. That is, on the condition that the W flag is -1 (8176), the pressure solenoid 413 (
(see Fig. 1) (8177) and the lens array 40
0 is interposed between the erase device W14 and the photosensitive drum 61, the exposure lamp is turned off (8178), preparations for writing characters are made, and after reaching the image leading edge y1 (8180), the bit created in the above step 5138 is inserted. Based on the map table, each LED element of the eraser is turned on and off. 8182) Characters are written electro-optically, and the crimping solenoid 4
13 (8184), the lens array 400 is retracted from between the erase device 4 and the photosensitive drum 61, and returned to its 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 a lens array.

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

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

[Effects] As described in detail above, the present invention, in an eraser in which a large number of LED elements are arranged, diffuses the luminous flux by interposing a lens array between the LED light source and the photosensitive drum when writing characters. This prevents this from occurring and ensures sharpness at the boundaries of one character.

As is clear from the examples, according to the eraser of the present invention, when writing characters, etc., the lens array is arranged between the eraser and the photosensitive drum, so that diffusion of LED light is prevented, and the characters to be written are The boundary becomes sharp.

On the other hand, when editing copies such as erasing and trimming,
Since the lens array is ablated, ripples due to local non-uniformity of ablated charge are prevented.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an eraser according to an embodiment. Second
The figure is a perspective view illustrating the arrangement relationship between the eraser and the photosensitive drum. FIG. 3 is an explanatory diagram illustrating a method of writing characters using an eraser. FIG. 4 is an eraser drive circuit diagram. FIG. 5 is a perspective view of the editing input device. FIG. 6 is an explanatory diagram of the function of the lens array. FIG. 7 is an explanatory diagram of the configuration of a copying machine equipped with an eraser. FIG. 8 is an explanatory diagram of font patterns. Figure 9 Part 1 and Part 2
is a flowchart showing control of the CPU. 10th
The figures are copies of images when a lens array is not used and when it is used. FIG. 11 is an explanatory diagram of the relationship between the distance between the surface of the photoreceptor and the tip of the eraser and the intensity of irradiated light. 4...Erase\ilf 416...Spring 413...Solenoid

Claims (2)

[Claims] (1) An erase device for a copying machine, which is disposed between a charger near the surface of a photoconductor drum and a developing device, and lowers the potential of a predetermined portion of the surface of the photoconductor drum by exposing the erase device to light. The light emitting unit is made up of a large number of LED elements whose light emission can be individually controlled, arranged in the axial direction of the photoreceptor drum, and includes a lens array that prevents diffusion of light emitted from the LED elements, and a lens array that prevents the light emission of the LED elements from being diffused. An erase device for a copying machine, comprising a driving means interposed between an exposure light emitting section and the surface of the photoreceptor drum. (2) In claim 1, the exposure light emitting section is such that the width in the axial direction of the light output section of some consecutive LED elements is the same as that of the light output section of other LED elements. An erase device for a copying machine, characterized in that the width in the axial direction is smaller than the width of the erase device in the axial direction.