JP3441503B2 - Toner remaining amount detection device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner remaining amount detecting device in an electrophotographic type or electrostatic recording type image forming apparatus using a rotary developing device.

[0002]

2. Description of the Related Art In an electrostatic recording type image forming apparatus, an electrostatic latent image is formed on a surface of a photoconductor, and the electrostatic latent image is visualized as a toner image by toner supplied from a developing device. The toner image is transferred and fixed on a transfer paper. The toner used here is contained in a toner cartridge that forms a toner storage unit of the developing device, and the remaining amount of toner contained in this cartridge is detected by the toner remaining amount detecting device. Is replaced with a new toner cartridge containing a specified amount of toner.

By the way, in an apparatus for detecting a toner remaining amount by transmitted light in a monochromatic image forming apparatus using an electrophotographic system, a device provided with a cleaning member (for example, a special device) as a device capable of sure detection. Kaisho 63-2
No. 087), a device that instantaneously increases the emission intensity (for example, Japanese Patent Application Laid-Open No. 2-114281), and the like are known.
However, the rotary developing device employed in the full-color image forming apparatus using the electrophotographic method rotates a plurality of disposable toner cartridges on the same rotation center line, and the residual toner of each toner in the rotary developing device is left. As a toner remaining amount detecting device for detecting the amount, there is no known device that can surely detect the remaining amount of toner in a non-contact manner by a common optical type detecting means.

[0004]

When the conventional single-color toner remaining amount detecting device as described above is applied to a full-color image forming apparatus equipped with a rotary developing device, for example, a cleaning member is used as a remaining amount detecting portion. In the method of providing, when the toner storage unit to be detected is a disposable toner cartridge, there is a problem that the cleaning member provided in the cartridge causes an increase in cost.

Further, when the method of increasing the light emission intensity is adopted, even though it is instantaneous, the light emitting element is still burdened and the life of the light emitting element may be shortened. An object of the present invention is to reliably detect the amount of remaining toner in an image forming apparatus such as an electrophotographic system or an electrostatic recording system provided with a rotary developing device that rotates together with a disposable toner cartridge, for example, a full color image forming apparatus. There is provided a device capable of realizing the above without increasing the cost. At the same time, another object is to provide an apparatus that does not impair the durability of the toner cartridge, the light emitting element, and the light receiving element.

[0006]

In order to achieve the above-mentioned object, the invention of claim 1 has a plurality of developing devices which are rotatably supported around a rotation axis and each contain a predetermined powder developer. And a cartridge provided corresponding to each developing device for supplying toner to the developing device, the plurality of developing devices are rotated together with the toner cartridges, and a predetermined developing device is provided as a latent image carrier. Is attached to an image forming apparatus equipped with a rotary developing device for bringing the electrostatic latent image formed on the latent image carrier into a visible image as a toner image by the developing device. The amount of toner remaining in each toner cartridge is arranged on the substrate so as to sandwich the outside of each toner cartridge.
In the toner remaining amount detecting device for non-contact detection by the detection method of the optical system common to each color using the element and the light receiving element ,
The distance between one of the toner cartridge wall surfaces and the light receiving element forming the detection means is shorter than the distance between the other toner cartridge wall surface and the light emitting element forming the detection means.

Further, the invention of claim 2 is characterized in that, in the toner remaining amount detecting device according to claim 1, a member for protecting the detecting means from the rotating toner cartridge is provided. Further, the invention of claim 3 is characterized in that, in the toner remaining amount detecting device according to claim 1, a guide member for restricting a deviation of the toner cartridge from a normal position is provided.

[0008]

According to the first aspect of the present invention, when the remaining amount of toner in each toner cartridge is detected in a non-contact manner by the optical type detection means common to the respective colors, which is attached to the outside of each toner cartridge, one of the toner cartridge wall surfaces is used. Since the distance between the light-receiving element forming the detecting means and the light-receiving element forming the detecting means is shorter than the distance between the other toner cartridge wall surface and the light-emitting element forming the detecting means, the light quantity itself of the light-emitting element is not increased but the toner cartridge wall surface and the light-receiving element are formed. It is possible to shorten the distance of and to relatively increase the amount of light received by the light receiving element.
Originally, the intensity of the received light changes depending on the distance between the light emitting element and the light receiving element. Therefore, in order to obtain a large amount of light, in addition to increasing the amount of emitted light itself, the distance between the light emitting element and the light receiving element may be reduced. However, since the light applied to the toner cartridge is scattered by the toner attached to the wall of the cartridge, the amount of received light also depends on the distance between the wall surface of the toner cartridge and the light receiving element. Therefore, if the distance between the light emitting element and the light receiving element is determined, the amount of light received increases when the light receiving element is closer to the wall of the toner cartridge, and the light emitting element is not burdened.

Furthermore, the invention of claim 2 is particularly characterized by claim 1.
Since the detecting means is provided with a member that protects the rotating toner cartridge, the detecting means is not destroyed by the toner cartridge that is mounted out of the normal position. Further, according to the third aspect of the invention, even if the toner cartridge of the first aspect is attached with being displaced from the normal position, the guide member of the toner cartridge is provided, so that the cartridge is not destroyed by the detecting means.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a rotary developing device equipped with a toner remaining amount detecting device according to the present invention. This rotary developing device is used in a full-color image forming device such as an electrophotographic system or an electrostatic recording system such as a copying machine or a printer. In this full-color image forming apparatus, electrostatic latent images of four colors of yellow, magenta, cyan, and black are formed on an image bearing member such as a photosensitive drum by an electrostatic latent image forming device including a charging device and an exposing device. These four-color electrostatic latent images are sequentially formed and developed by all the yellow, magenta, cyan, and black developing devices in the rotary developing device, and then superposed on a transfer material such as a transfer belt or transfer paper. Transfer to form a full-color image. In this case, all the developing devices of yellow, magenta, cyan, and black are set at the developing position in accordance with the electrostatic latent image of each color on the image carrier, and the electrostatic latent image of each color is developed to develop the image of each color. I am trying.

In the rotary developing device, all the developing devices for yellow, magenta, cyan and black are cylindrical case 2
And these developing devices are integrally mounted around a rotation shaft 12 centering on the rotation axis X and rotatably supported. This rotary developing device is rotationally driven by a stepping motor (not shown) at the time of development, and all the developing devices of yellow, magenta, cyan, and black rotate about the rotation axis X, and at the same time, the toner that supplies the developer to each developing device. Cartridge 1Y / 1M / 1C /
Rotate 1K. Each cartridge 1Y, 1M, 1
C-1K is formed of a light-transmissive resin material. All the yellow, magenta, cyan, and black developing devices are rotationally driven and set in a developing position facing the opening 10 of the case 2 to enable development,
Each contains a developer consisting of toner of each color such as powdery yellow toner, magenta toner, cyan toner, and black toner and a carrier (or a developer consisting of toner of each color), and the development is performed by these developers. be able to. Note that FIG. 1 shows a state in which the yellow developing device 11 is arranged in the opening 10.

A toner remaining amount detecting device is provided to detect the presence / absence of toner in each of the toner cartridges 1Y, 1M, 1C, and 1K that form the essential part of these rotary developing devices.

The detecting means 3 of the toner remaining amount detecting device is arranged in the vicinity of the locus A drawn by the outer periphery of each toner cartridge 1Y, 1M, 1C, 1K when the toner cartridge 1Y, 1M, 1C, 1K rotates, and each toner cartridge when the rotary developing device rotates. 1Y / 1M / 1C
1K sequentially passes through the detection position of the detection means 3. As shown in FIG. 2, the detection unit 3 is not in contact with the toner cartridge 1 (which represents a common member of the toner cartridges 1Y, 1M, 1C, and 1K), and includes a set of a light emitting element 4 and a light receiving element 5. Have. FIG. 3 shows an enlarged view of the detection means 3. The light emitting element 4 and the light receiving element 5 are mounted on the fixed circuit board 6 so as to face each other. The light emitting element 4 is an infrared light emitting diode, the light receiving element 5 is a photodiode, and the photoelectric conversion characteristics thereof are suitable for the infrared light emitting diode. The light emitting element 4 and the light receiving element 5 face each other with a narrow interval, and each toner cartridge 1Y, 1M, 1C
・ It is arranged so that the lower end in the direction of gravity is sandwiched when 1K is stopped. The light flux emitted from the light emitting element 4 passes through the lower end portion of the toner cartridge 1 made of a light transmissive resin material and is received by the light receiving element 5, and the presence or absence of the toner T in the toner cartridge 1 is detected in a non-contact manner. .

Here, considering the light quantity and layout,
The distance L1 between the light emitting element 4 and the light receiving element 5 is made as small as possible. For example, when the distance L1 is 40 mm, the distance L2 between the one wall surface of the toner cartridge 1 and the light emitting element 4
Is 25 mm, the distance L3 (<L2) between the other wall surface of the toner cartridge 1 and the light receiving element 5 is 7 mm, and the optical path length L4 in the toner cartridge 1 is 8 mm.
The distance L1 between the light emitting element 4 and the light receiving element 5 and the distance L between one wall surface of the toner cartridge 1 and the light emitting element 4
2. The distance L3 (<L2) between the other wall surface of the toner cartridge 1 and the light-receiving element 5 and the optical path length L4 in the toner cartridge 1 should satisfy the condition of L3 <L2, and An appropriate value is appropriately set according to the photoelectric conversion characteristics of the light receiving element 5 and the light transmission characteristics of the toner cartridge. By thus reducing the distance L3 between the other wall surface of the toner cartridge 1 and the light receiving element 5,
It is possible to make the received light amount relatively large without increasing the emitted light amount itself. That is, it is possible to increase the difference in output between the portion with toner and the portion without toner, and increase the margin of detection.

In FIG. 3, a light-shielding plate-shaped protection member 7 supported by the circuit board 6 is disposed in front of the light emitting element 4 (on the side facing the toner cartridge). The protective member 7 has an inner diameter of 2 m for narrowing the diameter of the light beam at the center of the vertical wall 700.
m holes 8 are formed, and guide surfaces 701 are formed at the ends. Here, the light flux from the light emitting element 4 is narrowed down by passing through the hole 8, whereby the diffusion of light can be reduced, and it is possible to prevent the light receiving element 5 from receiving irregularly reflected light and causing an erroneous detection. Further, the guide surface 701 of the protection member 7 functions as a guide member, and when the toner cartridge 1 shifts from the normal position and rotates while being bent and attached, the toner cartridge 1 is oriented in the correct direction, that is, the toner cartridge. The outer peripheral portion of is curved so as to play a role of rotating along a locus A drawn at a normal position. Therefore, the light-emitting element 4 is protected by the protection member 7 and is not destroyed even if the toner cartridge 1 rotates while being bent and attached while deviating from the normal position. At the same time, the toner cartridge 1 also serves as a guide member. It is guided by the surface 701 and is not destroyed by the light emitting element 4. That is, the protective member 7 protects the light emitting element 4 and also functions as a guide member for the toner cartridge 1.

The same applies to the light-receiving element 5 side, and a light-shielding plate-shaped protection member 9 supported by the circuit board 6 is provided in front of the light-receiving element 5 (on the side facing the toner cartridge), and a vertical wall of the protection member 9 is provided. A hole (not shown) through which the transmitted light of the toner cartridge passes is formed in the center of 900, and a guide surface 901 serving as a guide member is formed at the end. In this case as well, the protective member 9 plays a role of correcting the guide surface 901 of the toner cartridge 1 so that the toner cartridge 1 is rotated in the correct direction, that is, the outer peripheral portion of the toner cartridge is rotated along the locus A drawn at the normal position. It is possible to protect the cartridges 1 from destroying each other. In addition,
These protective members 7 and 9 also have the effect of preventing erroneous detection caused by toner scattered at the same time when the toner cartridge rotates and adhering to the detection surface and contaminating it.

In the above description, the light emitting element is formed of an infrared light emitting diode and the light receiving element is formed of a photodiode having a photoelectric conversion characteristic suitable for the infrared light emitting diode. The light emitting element is an incandescent lamp and the light receiving element is an incandescent lamp. It may be formed by a photodiode having a photoelectric conversion characteristic suitable for a lamp.

[0018]

As described above, according to the first aspect of the present invention, the distance between one cartridge wall surface and the light receiving element is shorter than the distance between the other cartridge wall surface and the light emitting element, so that light is emitted. The amount of light received by the light receiving element can be made relatively large without increasing the light amount of the element itself, and the amount of light received can be increased without increasing the amount of light itself, and toner residual amount can be achieved without increasing the cost. It is possible to prevent erroneous detection of the amount and extend the life of the light emitting element and the light receiving element. According to the second aspect of the invention, the toner cartridge attached while being displaced from the normal position rotates and collides with the detecting means,
It is possible to prevent the detection means from being destroyed and ensure the durability of the light emitting element and the light receiving element. According to the invention of claim 3, it is possible to prevent the toner cartridge, which is attached while being bent, from rotating and hitting the detection means, thereby preventing the toner cartridge from being destroyed and ensuring the durability of the light emitting element and the light receiving element. .

[Brief description of drawings]

FIG. 1 is a perspective view of a rotary developing device equipped with a toner cartridge provided with a toner remaining amount detecting device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a main part of the toner cartridge in FIG.

3 is an enlarged perspective view of the periphery of a light emitting element and a light receiving element of the toner remaining amount detecting device attached to the rotary developing device of FIG.

[Explanation of symbols]

1Y toner cartridge 1M toner cartridge 1C toner cartridge 1K toner cartridge 2 tubular case 3 detection means X rotation axis 4 Light-emitting element of detection means 5 Light receiving element of detection means 6 circuit board 7 Protective member that covers the light emitting element 700 Vertical wall on protective member 701 Guide surface forming a guide member 82 mm hole 9 Protective member that covers the light receiving element 900 Vertical wall on the protection member 901 Guide surface forming a guide member 12 rotation axes T toner L2 Distance between toner cartridge wall and light emitting element L3 Distance between toner cartridge wall and light receiving element

Claims (3)

(57) [Claims] 1. A plurality of developing devices which are rotatably supported around a rotation axis and each contain a predetermined powder developer, and the developing devices are provided corresponding to each developing device in order to replenish toner to the developing devices. And a plurality of developing devices are rotated together with the toner cartridges to bring a predetermined developing device to a developing position facing the latent image carrier, and the developing device forms the latent image carrier. An electrostatic latent image is visualized as a toner image and is attached to an image forming apparatus equipped with a rotary developing device. The toner remaining amount of each rotating toner cartridge is sandwiched between the outside of each toner cartridge. Light-emitting element placed on the substrate
In a toner remaining amount detecting device for non-contact detection by means of an optical method common to all colors using a light receiving element, the distance between one toner cartridge wall surface and the light receiving element forming the detecting means is the other toner. A toner remaining amount detecting device characterized in that the distance is shorter than the distance between the cartridge wall surface and the light emitting element forming the detecting means. 2. The remaining toner amount detecting device according to claim 1, further comprising a member for protecting the detecting means from a rotating toner cartridge. 3. The toner remaining amount detecting device according to claim 1, further comprising a guide member for restricting a deviation of the toner cartridge from a normal position.