JPH03126967A - Electrophotographic device - Google Patents

Abstract

PURPOSE:To simplify structure by making the best use of a part of laser beam serving as an exposing means for latent image formation to detect toner quantity. CONSTITUTION:The laser beam 10 emitted from a laser driving unit 1 forms a latent image on a photosensitive body 2. A mirror 7 is held in a position which does not block a route of the laser beam 10 to the photosensitive body 2 at a time of forming a latent image on the photosensitive body 2, whereas the laser beam 10 is deflected toward a developing device 2 at a time of forming no latent image. Then, the laser beam 10 is led to the toner feeding part of the developing device 3 via a light transmitting window 3a, the laser beam passing through the toner supply part is taken out of the light transmitting window 3b and grasped by a photodetecting device 4. Ultimately, the residual quantity of the toner is discriminated and displayed on a display part 5. Thus, the constitution is simplified.

Description

[Detailed Description of the Invention] 4 Tojo △ and Kaidama 1 The present invention generally relates to an electrophotographic device,
In particular, the present invention relates to an electrophotographic apparatus in which a latent image is formed using a laser beam as an exposure means, and the latent image is visualized by a developing device equipped with a remaining toner amount detecting device.

Antenna type and optical type are conventionally known as remaining toner amount detection devices provided in developing devices of electrophotographic apparatuses. In particular, the optical system employed in the present invention is configured as shown in FIG.

That is, in the electrophotographic apparatus of this example, the developing device 3 is provided adjacent to the drum-shaped electrophotographic photoreceptor 2, and develops the latent image formed on the photoreceptor 2. On the other hand, the developing device 3 is provided with light transmitting windows 3a and 3b, and the light beam 11 from the light source 9 is introduced into the toner supply section of the developing device 3 through the light transmitting window 3a.
Then, the light beam 11 that has passed through the toner supply section is transmitted to the light transmitting window 3b.
A light detection means 4 taken out from the light source and provided on the opposite side from the light source 9
This is captured and the remaining amount of toner is determined and displayed on the display section 5.

In this case, if there is enough toner in the toner supply section, the light beam 11 cannot reach the light detection means 4, so it is determined that the remaining amount of toner is sufficient, and the display section 5 also displays this. As the amount of light transmitted through the toner supply section decreases, the amount of light transmitted to the toner supply section gradually increases, and when the light detection means 4 detects a value greater than or equal to the value, it is determined that the remaining amount of toner is insufficient, and the display section 1 displays a message to that effect. do.

However,
In the above-mentioned conventional technology, a lamp, an LED, etc. are used as the light source 9, and a drive circuit for emitting light is required, which not only requires extra power, but also has a limited lifespan of the lamp itself. This must be replaced.

Moreover, if the lamp burns out, it becomes impossible to check the amount of toner, so it is necessary to further provide a detection means for detecting lamp burnout.

Therefore, an object of the present invention is to detect the amount of toner by utilizing a portion of the laser light in an electrophotographic apparatus that uses laser light as an exposure means for forming a latent image. By providing an electrophotographic device that eliminates the need for a separate circuit, simplifies the structure, and avoids unexpected situations such as lamp burnouts, and that can always obtain stable, high-quality images. be.

in order to The above object is achieved by an electrophotographic apparatus according to the present invention.

In summary, the present invention provides an electrophotographic apparatus that uses laser light to form a latent image on an electrophotographic photoreceptor and develops the latent image using a developing device, in which a portion of the laser light is used for developing. An electrophotographic apparatus characterized in that a detection means detects the amount of light after the laser beam passes through the developing device, thereby detecting the amount of toner remaining in the developing device. .

DESCRIPTION OF THE PREFERRED EMBODIMENTS Below, the electrophotographic apparatus according to the present invention will be explained in more detail with reference to the drawings.

In the electrophotographic apparatus of this embodiment shown in FIGS. 1 and 2, a developing device 3 is located adjacent to a drum-shaped electrophotographic photoreceptor 2.
is provided to develop the latent image formed on the photoreceptor 2.

Around the photoreceptor 2, there are image forming means such as a latent image forming means for forming a latent image and, if necessary, a transfer means for transferring the image formed on the photoreceptor to a transfer material. However, since such image forming means are well known to those skilled in the art, they are not shown in FIG. 1, and only the laser drive unit 1 constituting the exposure means is shown.

That is, according to the present invention, as described above, the laser beam 1o emitted from the laser drive unit 1 forms a latent image on the photoreceptor 2, and this latent image is developed with the toner supplied from the developing device 3. be converted into

In this embodiment, a mirror 7 rotated by a drive shaft 8 is disposed in the optical path of the laser beam 10 between the laser drive unit 1 and the photoreceptor 2. The mirror 7 receives the laser beam 10 by driving and controlling the drive shaft 8.
At the time when the laser beam 10 forms a latent image on the photoreceptor 2, the laser beam 10 is located at a position that does not block the path of the laser beam 10 to the photoreceptor 2, that is,
In the figure, it is held at the position indicated by the symbol (B), and when a latent image is not formed, it is moved to the position indicated by the symbol (A) in the figure.
The laser beam 1o is deflected toward the developing device 3.

On the other hand, the developing device 3 is provided with light transmission windows 3a and 3b, and when the mirror 7 is in the position (A), the laser beam 10 is transmitted through the mirror 7.
The light beam 1 is reflected by the light transmitting window 3a and introduced into the toner supply section of the developing device 3, and then passes through the toner supply section.
1 is taken out from the light-transmitting window 3b, captured by the light detection means 4 provided facing the light-transmitting window 3b, and the remaining amount of toner is determined and displayed on the display section 5.

Therefore, according to this embodiment, the amount of toner in the developing device 3 can be detected only by controlling the position of the mirror 7. That is, if the amount of toner is sufficient, the laser beam 10 will be absorbed by the toner and will not reach the light detection means 4. Further, as the amount of toner decreases, the amount of laser light passing through the developing device 3 gradually increases. Therefore, when the light detection means 4 detects an amount of light exceeding the value, it is determined that the amount of toner is insufficient, and a message to that effect is displayed on the display section 5.

A second embodiment of the invention is shown in FIG. In this embodiment, in place of the mirror 7 of the previous embodiment, a half mirror 21 having a width corresponding to the scanning width in the main scanning direction of the laser beam is installed at the position corresponding to (A) in FIG. It is arranged in a fixed position and is configured to reflect a part of the laser light toward the light transmission windows 3a and 3b regardless of whether a latent image is formed or not.

According to this embodiment, it is necessary to increase the output of the laser light from the laser drive unit 1 so that the amount of exposure for forming a latent image is not insufficient. Unlike the embodiment, a control system for driving the shaft 8 is not required. Further, according to this embodiment, the light transmitting window 3a allows all the reflected light from the half mirror 22 to enter the developing device 3 so that the laser light reflected by the half mirror 22 does not become backlight and adversely affect image formation. In order to guide the image, it is made longer in the main scanning direction.

In this embodiment as well, the amount of toner in the developing device 3 is detected in the same manner as in the previous embodiment. Although toner detection may be performed simultaneously when an image is formed, it is preferably performed by outputting a laser beam when an image is not formed.

Another embodiment of the invention is shown in FIGS. 4 and 5.

In this embodiment, the scanning width in the main scanning direction of the laser beam 10 emitted from the laser drive unit l is expanded beyond that required for latent image formation, and the scanning width is expanded to a position unrelated to latent image formation, that is, a non-image. As shown in FIG. 5, a reflecting mirror 23 is fixedly provided on one side of the area to reflect the laser beam 10 and introduce it into the developing device 3 through the light transmission window 3a.
Next, the light is made to enter the light detecting means 4 through the light transmitting window 3b. The remaining amount of toner is detected in the same manner as in the previous embodiment.

In this embodiment, it is possible to detect the remaining amount of toner even when a latent image is being formed.

Yet another embodiment of the invention is shown in FIGS. 6 and 7.

In this embodiment, instead of the mirror 23 in the embodiment shown in FIGS. 4 and 5, a conical reflecting section 24 is attached to one side of the photoreceptor 2, and the reflecting section 24 reflects the laser beam. Constructed to be reflective.

The laser beam IO reflected by the reflection section 24 passes through the light transmission windows 3a and 3b of the developing device 3 and enters the light detection means 4, as in the previous embodiment.

Note that in this embodiment, the laser beam 10 is
4 and guide it to the developing device 3, it is necessary to shift the rotation center of the photoreceptor downward relative to the laser beam 10, but this may distort the laser spot on the photoreceptor. Become. Therefore, it is necessary to correct the laser spot in the optical system of the laser drive unit 1.

In this embodiment, it is possible to detect the remaining amount of toner even when a latent image is being formed.

(As explained above, when the electrophotographic apparatus according to the present invention uses laser light as an exposure means, the electrophotographic apparatus detects the amount of toner remaining in the developing device by using the laser light.) Because of this structure, the structure is simple and costs can be reduced.

Further, according to the present invention, unlike the conventional case where a special lamp or LED is used to detect the remaining amount of toner, it is possible to detect the remaining amount of toner with high reliability, and a high-quality image can always be obtained. be able to.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view showing an embodiment of an electrophotographic apparatus according to the present invention. 2 is a bottom view of the apparatus of FIG. 1; FIG. FIG. 3 is a bottom view of another embodiment of the electrophotographic apparatus according to the present invention. FIG. 4 is a schematic side view showing another embodiment of the electrophotographic apparatus according to the present invention. 5 is a bottom view of the apparatus of FIG. 4; FIG. FIG. 6 is a schematic side view showing still another embodiment of the electrophotographic apparatus according to the present invention. 7 is a bottom view of the apparatus of FIG. 6; FIG. FIG. 8 is a schematic side view of a conventional device. l: Laser drive unit 2: Photoreceptor 3: Developing devices 3a, 3b: Light transmission window 4: Light detection means 5: Display section 7.21.22.23: Mirai member 10: Laser light Fig. 2, Fig. 3 Figure 4 3 Figure 5 Figure 6 z4 Figure 7 4

Claims (1)

[Claims] 1) In an electrophotographic device that uses laser light to form a latent image on an electrophotographic photoreceptor and visualizes the latent image in a developing device, a portion of the laser light is guided to the developing device and the latent image is visualized by a developing device. An electrophotographic apparatus characterized in that a detection means detects the amount of laser light after passing through the developing device, and thereby detects the amount of toner remaining in the developing device.