JPS61285477A - Electrostatic recording device - Google Patents

Abstract

PURPOSE:To obtain a latent image other than an original with a small output by arranging an exposing means for forming images other than original images on the lower side of a uniform electric charging means along the moving direction of a photosensitive body and arranging an exposing means for forming an original image on an area other than an image forming area on the more lower side. CONSTITUTION:An original platen 2 is arranged on the upper surface of a copying machine body 1 and a photosensitive drum 13 is rotatably set up on the almost center of the body 1. A short focus lens array 14 for forming an image of an original set up on the original board 2 is vertically set up at the upstream side of the drum 13. An LED array 15 for forming an electrostatic latent image other than an original image on the drum 13 and a short focus lens array 58 for forming the image formed by the array 15 on the drum 13 are arranged at the up stream side of the lens array 14. In addition, a charging corotron 16 for plus charging the drum 13 uniformly is fixed on the upper side of the lens array 58. Thus, the latent image other than the original image is formed during the holding time of the drum 13 at high sensitivity and the latent image other than the original image can be formed with a small output.

Description

DETAILED DESCRIPTION OF THE INVENTION B) Field of Industrial Application The present invention relates to an electrostatic recording apparatus equipped with means for forming an electrostatic latent image other than an original image.

(B) Conventional technology An electrostatic recording apparatus equipped with a means for forming an electrostatic latent image other than an original image has already been proposed by the applicant of the present application (see Japanese Patent Application No. 58-241203).

In the electrostatic recording device proposed here, the means for exposing the original image is located upstream along the moving direction of the photoreceptor than the means for exposing images other than the original image, or the means for exposing the original image is located at the same position as the means for exposing the image other than the original image. located in the area.

By the way, the charged potential of the photoreceptor is as shown in FIG.
Even if it is not exposed to light, it will attenuate over time as the photoreceptor moves. The photoreceptor is made of amorphous silicon, the vertical axis represents the charging potential (V), and the horizontal axis represents time (the distance traveled by the photoreceptor).

As can be seen from this figure, in the case of an amorphous silicon photoreceptor, the charging potential decreases to about 200 μ after 1.5 seconds have elapsed after being charged. By the way, when a photoreceptor is irradiated with light of the same light energy, there is a difference in the attenuated potential (sensitivity) between 0.5 seconds and 3 seconds after charging. Specifically, when 0.5 seconds have elapsed after charging, the attenuation is about 100 cm, but when 3 seconds have elapsed, the attenuation is only about 30 inches.

(c) Problems to be Solved by the Invention As mentioned above, the charged potential on the photoreceptor rapidly attenuates after being charged, and the higher the potential, the greater the attenuation upon exposure (that is, the higher the sensitivity). Therefore, when exposing with a light source of low output, the light source should be provided as close to the charging means as possible.

However, in the conventional technology, as mentioned above, the exposure means (specifically, the LE
D array) is located downstream of the exposure means that forms a high-output original image.

Therefore, it was necessary to increase the output of the exposure means that forms images other than the original image, but if this exposure means is constituted by an LED array, it is not easy to increase the output of the exposure means.

(d) Means for Solving the Problems The present invention provides a photoreceptor, a means for uniformly charging the photoreceptor, and a first method for forming an image other than an original image on the charged photoreceptor. An exposure means and a second exposure means for forming an original image in an area other than the image forming area of the photoreceptor are provided, and the first exposure means is arranged to expose the charging means along the moving direction of the photoreceptor. The second exposure means is an electrostatic recording device located further downstream than the first exposure means.

(E) Function In the present invention, a latent image of an image other than the original image is formed while the photoreceptor maintains high sensitivity, so 1. A desired latent image can be formed using a low output exposure means.

(F) Embodiment FIG. 1 is a perspective view showing the appearance of an embodiment of the present invention, and FIG. 2 is a plan view showing the display section thereof. In these figures, (1) is the copying machine main body;
) is slidably mounted on the upper surface of the document table (2), which can be moved left and right.

(3) is a paper cassette that can hold and store copy paper; (4)
) is the paper output tray. Also, () on the operation panel (5)
6) is a numeric keypad for specifying the number of copies, and (7) is a selection key for printing selection used when selecting an image other than the original image (for example, date or company name). Display panel (8)
Above (9) is a 7-segment display element for displaying the number of copies, and (10) is a 7-segment display element for displaying designated print content by number.

FIG. 3 is a diagram showing the printed contents corresponding to the selection keys (7). In this figure, selection key (7)...
The numbers above the * indicate the printed content. Therefore, if the operator, for example, selects the key number 5 (
By operating 7), the date will be printed on the copy paper in addition to the original image. Similarly, select key number 8 (
If you operate 7), the address will be printed. The printed content corresponding to each selection key (7) is as follows:
It is assumed that the information is stored in advance in a read-only memory (ROM).

Figure 4 shows the selection key (7)... and this selection key (
7)... is a diagram showing the correspondence with the contents printed on copy paper (11) by operating. Figure 4 (A
), press the selection key (7)... as the key number changes from 3 to 4.
→ If you operate in the order of 5 → 6 → 8, copy paper (11)
The text as shown on the right side (III (with respect to the direction of travel)) can be printed out. Also, in Fig. 4 (B),
Select key (7)...key number is 1→3→6→9→4
When the operations are performed in this order, the text in English characters as shown in this figure is printed on the right side of the copy paper (11). Furthermore, in FIG. 4(C), when the selection keys (7)... are operated in the order of key numbers 2 → 10 → 7-11,
Vertical text as shown in this figure is printed on the right side of the copy paper 11).

Figure 5 is a sectional view showing the internal structure of the electronic copying machine, (2)
is a document table made of a transparent glass plate which is attached to the top surface of the copying machine body (1) so that it can be moved freely in the left and right direction, and a cover (12) is attached to the top surface of this document table (2), which can be opened and closed freely. It is installed. A photoreceptor drum (13) having an amorphous silicone photoreceptor with an M-taing formed on its circumferential surface is rotatably mounted approximately in the center of the copying machine main body (1).

A second exposure means is provided on the top of the photosensitive drum (13) for forming an image of the document placed on the document table (2) on the circumferential surface of the photosensitive drum (13). A short focus lens row (14) is vertically provided. This short focus lens array (
On the upstream side of 14), there is a monolithic light emitting diode array (hereinafter referred to as an LED array) <15) as a first exposure means for forming an electrostatic latent image other than the original image on the photoreceptor drum (13). A second short focus lens array (58) is provided for projecting and forming an image other than the original image formed by the LED array (15) onto the photoreceptor drum (13). Note that the detailed configuration of this LED array (15) will be described later.

This LED array (15) is provided with a light shielding plate (67) that shields the light rays that form the integrated original image. Further, on the upstream side of the short focus lens row (14), a photoreceptor drum (13) is uniformly positively charged (approximately 600 V).
A charging corotron (16) is fixedly installed for charging, and above the charging corotron (16) is an exposure lamp (halogen lamp) (17) as a second exposure means for illuminating the document surface. It is equipped.

(1B) is a filter of this exposure lamp (17).

The charging corotron (16) and the exposure lamp
17), an electrostatic latent image of the original has been formed on most of the surface of the photoreceptor drum (13) by the short focus lens array (14) and the original, and the LED array (15) ) An electrostatic latent image other than the original image is formed on a portion of the image.

A developing device (19) for developing the electrostatic latent image with toner is provided downstream of the short focus lens array (14). This developing device (19) stores a mixture (developer) of toner and carrier (20), and this developer (20) is negatively charged toward the photoreceptor drum (13) by a magnet roller (21). It can be transported without breaking. At this time, a developer (20) is formed on the part of the magnet roller (21) facing the photoreceptor drum (13), and the tip of the developer contacts the photoreceptor drum (13), generating a positive charge. The image of the original document and other images are developed by applying the residual image formed by the toner to the negatively charged toner image as a latent image. (22) is the developer (
20) is a blade that controls the height of the panicle. In addition,
The developing device (19) contains two types of toner having different components, and this point will be described later.

A paper feed cassette (3) in which copy paper (11) is loaded and stored is removably attached to the right end of the copying machine main body. At the bottom of this paper feed cassette (3), copy paper (11
) is mounted on the support plate (23), and the base end of the support plate (23) is swingably attached to the inner bottom of the copying machine body (1). An opening (25) is provided through which the free end of the pushed-up lever (24) can be inserted. The push-up lever (24) is equipped with a spring (not shown) that biases the push-up lever (24) clockwise.
The support plate (23) is urged upward by this spring. Above the downstream end of the paper feed cassette (3), there is a paper feed roller (
26) is provided, and the uppermost copy paper (11) is pressed against the lower part of this paper feed roller (26) by the push-up lever (24).

On the downstream side of the paper feed roller (26), the copy paper (11) fed from the paper feed cassette 3) is temporarily stopped and then synchronized with the operation of the document table (2). A pair of register rollers (27) (27) for refeeding is provided. (28) is a reflective photosensor that detects the presence or absence of copy paper (11).

A transfer corotron (29) is provided at the lower end of the photosensitive drum (13) for transferring the toner image developed by the developing device (19) onto copy paper (11). A peeling corotron (30) for peeling the copy paper (11) from the photosensitive drum (13) is arranged adjacent to the downstream side of the transfer corotron (29).

A vacuum conveyor (31) for conveying the copy paper (11) on which the toner image has been transferred is provided downstream of the peeling flotron (30), and the copy paper (11) on which the toner image has been transferred is This conveyor <31) is used as a fixing device! f
It is transported toward f1 (32).

The fixing device (32) is composed of a heat roller (34) with a built-in heater (33) and a pressure roller (35) that is in pressure contact with the heat roller (34), and the fixing device (32) is made up of a heat roller (34) with a built-in heater (33), and a pressure roller (35) that is pressed against the heat roller (34). are both rollers (34) (35
) and is heated under pressure and fixed. (36) is an offset fat stopper that prevents the fixed copy paper (11) from being offset to the heat roller (34). A pair of paper discharge rollers (37) (37) for discharging the fixed copy paper (11) is provided downstream of the heat roller (34). (3B)
is a detection switch that detects copy paper (11).

Above the vacuum conveyor (31), copy paper (1
1) is provided with a cleaning device (39) for removing toner that has not been completely transferred and remains on the photosensitive drum (13). This cleaning device (39) includes a cleaning blade (40) that scrapes off residual toner on the photoreceptor drum (13), and a cleaning blade (40) that scrapes off residual toner on the photoreceptor drum (13).
) to the toner storage box (41).
It consists of a roller (42) that conveys the

Then, the selection key (7) on the operation panel (5)...
After pressing a desired one of ., placing the original on the original table (2) and pressing the start button (43) (Fig. 1), the exposure scanning of the original is performed. In other words, the manuscript table (2
> moves to the left and then to the right, and during this movement to the right, the original is fully exposed and scanned, and the original image is transferred onto the photoreceptor drum (13) by the short focus lens array (14). An electrostatic latent image corresponding to the original image is formed. At this time, the LED array (15) selectively emits light,
An electrostatic latent image of content (for example, date, etc.) corresponding to the operated selection key is simultaneously formed on the photoreceptor drum (13).

The document thus formed and the electrostatic latent image of the wording etc. selected by the selection key are developed with toner in a developing device (19). This toner image is then transferred by a transfer corotron (29) onto the copy paper (11) that has been completely conveyed by the pair of register rollers (27) (27). The copy paper (11) on which the toner image has been transferred is peeled off from the photosensitive drum (13) by a peeling flotron (30), and then transferred to a fixing device (
32), and is fixed by a heating roller (34) and a Calorie pressure roller (35). The copy paper (11) that has been fixed in this way is moved to a pair of paper ejection rollers (37) (37).
The paper is discharged onto the paper discharge tray (4) (FIG. 1).

Note that the photosensitive drum (11) was not completely transferred to the copy paper (11)
13) The toner remaining on the surface is removed by the cleaning device (
39), and the cleaned photosensitive drum (13) is uniformly newly charged with a positive charge by the charging Flotron (16).

Figure 6 shows the LED array (15) and short focus lens array (14).
) is shown when cut in a direction perpendicular to the axis of the photoreceptor drum 13). (47) is an alumina substrate to which an LED array (15) is fixed, and this alumina substrate (47) is It is fixed to an aluminum fixing base (48) which also serves as a radiation fin. On the alumina substrate (47), on the left and right sides of the LED array (15), there are driver Is for driving the LED array (15).
C (49) (49) is completely fixed and funecta (5
0), a flat cable (51) is connected thereto. At the bottom of the fixed stand (48) is an LED array (15).
A transparent glass plate (52) is attached to protect the parts and the like.

Figure 7 shows the LED array (15) and short focus lens array (14).
), and FIG. 8 is a perspective view showing the alumina substrate (47). FIG. 9 is a perspective view showing the alumina substrate (47).
15), in which (53)... are light emitting parts, and (54)... are electrodes. These electrodes (5
4)... are connected to the pattern wiring (56) on the alumina substrate (47) via gold wires (55)...

The size of each light emitting part in this LED array (15) is 0.07 x O,08 (mn), the overall length is 14.84 (11111), and the pitch is 0.106 (ni).
l), and the number of dots is 128.

The LED array (15) is a red LED formed by mounting GaAs on a GaAsP base.
It is composed of the ED group, and the emission wavelength is approximately 6,600. Therefore, photoreceptors suitable for this purpose are limited to amorphous silicon having long wavelength characteristics, selenium having a high tellurium content, and the like. In this regard, if a green LED array (wavelength: 5650) is used, the range of types of photoreceptors that can be used with it will be expanded.

In Figure 6, TC is the conjugate length and zo is the lens (14)
The length 12o represents the distance from the end surface of the lens (14) to the LED array (15) or photosensitive drum (13). The relationship between these dimensions and the wavelength of the LED is shown in the following table.

Note that a halogen lamp is used as the exposure lamp (17) for illuminating the surface of the document, and the center wavelength of this halogen lamp is approximately 5,500. Therefore green LE
The same short focus lens row can be used for the D array and the halogen lamp, but the length of the lenses used must be different for the red LED array and the halogen lamp, so the same short focus lens row (14) cannot be used.

FIG. 10 is a perspective view showing an embodiment in which an LED array (15) is provided on the side of a short focus lens array (14) for projecting and forming a document image. In this figure, the holder (44) blocks light from a portion of the photoreceptor drum (13) that corresponds to a portion on which an electrostatic latent image is formed other than the document image.

Furthermore, a dedicated short focus lens array (58) for projecting and forming an image formed by the LED array (15) and the LED play (15) is fixedly installed on the holder (44). By providing the dedicated short focus lens row (58) in this way, the LED array (15) can be connected to the photoreceptor drum (
13), and the height of the holder (44) can be lowered.

FIG. 11 is a side view corresponding to FIG. 10. (58)
is a dedicated short focus lens array for forming an electrostatic latent image other than the original image. If the LED array (15) is fixed to the short focus lens row (14) in this way, it is not possible to change the formation position of the electrostatic latent image other than the original image, but the LED array (15)
No mechanism or control circuit is required to move the D array (15), and the entire structure can be made compact.

FIG. 12 is a block diagram showing the control circuit. In this figure, the circuit configuration of the entire electronic copying machine is omitted, and only the circuit configuration for forming images other than the original image is shown. In order to form an image other than the original image, it is first necessary to operate the selection key (7) corresponding to the image other than the desired original image. Then, the central processing unit ic F'
U ) (60) allows read-only memory (RO
M > (61), the information corresponding to the image other than the original image is transferred to the read/write memory (RAM) (62), and further synchronized with the operation of the electronic copying machine, (RAM)
The information in (62) is transferred to the pattern generator (63). And by this pattern generator (63), the LED
A driver (64) drives and controls the monolithic LED array (15).
selectively repeats blinking, and a desired image is formed. The display (65) indicates the operating status of the electronic copying machine and the order in which images other than the original image are formed. Further, the mechanism control section (66) controls the entire operation of the electronic copying machine.

13(A) to P) according to an embodiment of the present invention! FIG. 7 is a plan view showing different embodiments of copy paper on which images other than manuscript images are formed;

Figure 13 (A> shows the characters ``A1.'' written in white on a black background, and Figure 13 (B) shows 1 in black letters on a white background.
A1" is formed.

When printing with an LED array in a printer or the like, a black print is usually formed only on the portion corresponding to the light emitting part of the LED by performing reversal development. However, in the case of an electronic copying machine, when reversal development is performed, the black and white of the original image is also reversed, which causes a problem. Therefore, in the case of the present invention, when forming white characters etc., it is sufficient to make the LED array emit light corresponding to the characters, but when forming ordinary characters, it is sufficient to make the LED array emit light corresponding to the background. It is necessary to make the LED array emit light.

FIG. 13(C) shows an example in which the company name is printed on the left end, and FIG. 13(D) shows an example in which the LED array is moved and the postal code is printed horizontally in the center.

Fig. 13 (E) shows an example of printing the company name and location name near both edges of the copy paper using two LED arrays, and Fig. 13 (F) shows an example of printing the company name and location name near both sides of the copy paper, and Fig. 13 (F) shows the printing of the company name and location name using two LED arrays. An example of what is printed at the position is shown below.

Figures 13 (G) and (H) show examples of patterns other than letters formed near the right edge, and Figure 13 (I) shows a combination of vertically written characters and horizontally written characters near the right edge. An example of what is printed is shown below.

FIG. 13(J) shows an example of printing near the right edge of copy paper of various sizes.

Figure 13 (K), (L), and (M>) show examples of printing with the electronic copying machine operating at different copying speeds; (K) is the one printed at the slowest speed, and (M) is the one printed at the highest speed. An example is shown.

FIG. 13(N) shows an example with a frame, and FIG. 13(0) shows an example with a scale near the right end.

And, Figure 13 (P) is from the leading edge of the copy paper! An example is shown in which printing is started from a position separated by .

(G) Effects of the Invention In the present invention, since the second exposure means is located upstream of the first exposure means, that is, on the side of the charging means, the original is A latent image of an image other than the image is formed.

Therefore, even if the first exposure means has a low output such as an LED, it is possible to clearly form a latent image on a surface other than the original.

[Brief explanation of the drawing]

The drawings all show embodiments of the present invention, and FIG. 1 is an external perspective view, FIG. 2 is a plan view showing the display section, FIG. 3 is a view showing the inside of the print corresponding to the selection key, and FIG. 5 is a cross-sectional view showing the internal structure of the electronic copying machine; FIG. 6 is a cross-sectional view showing the short focus lens array and the LED array; Figure 7 shows LED
FIG. 8 is a perspective view showing the alumina substrate; FIG. 9 is a partially enlarged view showing the LED array;
Fig. 10 is a perspective view showing another embodiment of the LED array, Fig. 11 is a side view corresponding to Fig. 1O, Fig. 12 is a block diagram showing the control circuit, Fig. 13 (A) to P). 14 is a plan view showing a copy sheet on which an image other than the original image is formed;
The figure is a graph showing the relationship between the first charge and time. (1)...Copy machine body, (2)...Document stand, (13
)...Photosensitive drum, (14)...Short focal length lens row (second exposure means), (15)...LED play (first exposure means), (17>...Exposure lamp (second exposure means), (19)...developing device, (44>...L
ED array holder, (67)...Lead screw, (6
8)...Stepping motor.

Claims (1)

[Scope of Claims] 1. A photoreceptor, a means for uniformly charging the photoreceptor, a first exposure means for forming an image other than an original image on the charged photoreceptor, and a second exposing means for forming a document image in an area other than the image forming area, the first exposing means being located downstream of the charging means along the moving direction of the photoreceptor; The second exposure means is an electrostatic recording device located further downstream than the first exposure means. 2. The electrostatic recording apparatus according to claim 1, wherein the first exposure means has a smaller output than the second exposure means. 3. The electrostatic recording device according to claim 1 or 2, wherein the first exposure means is a light emitting diode, and the second exposure means is an exposure lamp that illuminates the document and a short focus lens array. .