JPH03197988A - Image forming device - Google Patents

Abstract

PURPOSE:To form a highly reliable and stable image under any ambient humidity condition by inputting information on change in humidity detected by a humidity sensor to a CPU and allowing the CPU to control the operation of a transfer means and its auxiliary means based on the information on the change in the humidity. CONSTITUTION:The humidity sensor 1 is provided in the vicinity of a transfer space, etc., and a voltage is outputted from the humidity sensor 1 according to the humidity and inputted into the control device 4 of the CPU 2. Programs for drive-controlling the transfer means and its auxiliary means 6 are compared by an arithmetic device 5 based on the inputted humidity condition and each humidity condition previously stored in the storage device 3. The arithmetic result is outputted to the control device 4 and the transfer means and its auxiliary means 6 are controlled. Thus, a highly reliable and stable image can be obtained regardless of fluctuation in the humidity.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) This invention relates to improvement of an electrostatic recording type image forming apparatus,
In particular, the present invention relates to an image forming apparatus configured to be able to faithfully transfer a toner image formed on an image carrier to a transfer sheet with high transfer efficiency without being affected by changes in humidity.

(Prior Art) An electrostatic recording type image forming apparatus has a configuration shown in FIG. That is, the drum 7 is placed around the drum 7 (hereinafter abbreviated as "drum") having a photosensitive film on its outer surface.
A charger 8 uniformly charges the outer surface of the drum 7 along the rotational direction (direction of arrow a), and a light beam such as a laser beam is irradiated onto the charged outer surface of the drum 7.
A light beam irradiation system 9 that eliminates the charge on the outer surface of the drum and forms an electrostatic latent image, and a developer that contains a developer and brings the developer into contact with the electrostatic latent image on the outer surface of the drum 7 to develop the toner image. In the space B between the device Fio and the drum 2, the drum 7
A transfer station 11 that contacts the upper toner image and transfers the toner image to the transfer sheet P, after transferring the toner image,
A cleaning device 13 for removing developer remaining on the drum 7, and a discharge lamp 14 for eliminating electric charges on the entire outer surface of the drum 7 after cleaning by the cleaning device 13 are provided.

In addition, in order to supply new developer to the developing device 1o,
A developer cartridge 15 is provided.

Further, the transfer sheet P on which the toner image has been transferred is transferred to a fixing device 19, heated, and sent to a tray after being fixed.

In order to improve the transfer efficiency of the toner image on the drum 7 to the transfer sheet P, the transfer station 11 of the conventional image forming apparatus described above not only increases the transfer voltage of the transfer means but also increases the transfer voltage as shown in FIG. As transfer auxiliary means, a pre-transfer static elimination lamp 16 and a bias voltage application means 17 are arranged downstream of the developing device 10 and upstream of the transfer station 6. to weaken the adhesion force and transfer the transfer sheet P.
In addition, the bias voltage applying means 17 applies a bias voltage to the transfer sheet P passing over the bias voltage applying means 17.
moisture absorption prevents voltage leaks.

(Problems to be Solved by the Invention) However, the pre-transfer charge eliminating chamber 16 and the bias voltage applying means 17 of the transfer station 11 of the conventional image forming apparatus described above do not perform exposure or Because it is configured to apply a bias, the humidity inside the image forming apparatus is not always normal humidity (about 45%), and depending on the work environment, it may be high humidity of 70% or more, or low humidity of 40% or less. to become or change a state. Under such work environments, users have traditionally taken measures such as replacing the transfer sheet P with one designed for high humidity, increasing the pre-transfer bias voltage, and increasing the transfer current. ing. Therefore, it is difficult to transfer the toner image onto the transfer sheet P efficiently.

This invention was made in order to solve the drawbacks of conventional image forming apparatuses having a transfer station configured as described above, and allows the user to easily transfer the transfer sheet P one by one in both high humidity and low humidity environments. An image forming device that can obtain high-quality images with high transfer efficiency and high reliability regardless of humidity fluctuations without the need to replace with a device specifically designed for high humidity or to increase the pre-transfer bias voltage. This is what we are trying to provide.

[Configuration of the Invention (Means for Solving the Problems) In order to solve the above problems, an image forming apparatus according to the present invention has the configuration shown in FIG. The output voltage of the humidity sensor 1 is manually input to the central processing unit (hereinafter simply abbreviated as rcPUJ) 2,
The configuration is such that the transfer means/transfer auxiliary means 6 of the image forming apparatus is controlled based on humidity versus transfer voltage information stored in the CPU 2 in advance.

(Function) As described above, the output voltage of the humidity sensor that generates a voltage depending on the humidity is input to the CPU 2, and the image forming apparatus is operated based on the humidity versus transfer voltage information stored in the CPU 2 in advance. Since the operation of the transfer means and the transfer assisting means is controlled, the transfer means and the transfer assisting means 6 are controlled in response to changes in humidity.
Not only can this be automatically and accurately controlled, but also the transfer efficiency to the transfer sheet can be improved.

(Embodiment) Next, an image forming apparatus according to an embodiment of the present invention will be described. However, in order to make the explanation easier to understand, the explanation will focus on the transfer station 6, which is the main part of the present invention, the pre-transfer static elimination lamp as transfer auxiliary means, the bias transmission applying plate, and the transfer sheet P.

FIG. 2 is a schematic block diagram of the image forming apparatus according to the embodiment, in which a charger 8, a light beam irradiation optical system 9, a developing device device 10, pre-transfer static elimination lamp 16, bias voltage applying means 17, transfer station 11, cleaning device 1
3 and a static elimination lamp 14 are arranged in this order, and in a space B between the drum 7 and the transfer station 11, a transfer sheet P fed from a paper feeding center (not shown) is placed near the drum 7 and placed on an aligning roller. The transfer sheet is conveyed to a fixing device (not shown) along a transfer sheet conveyance path 21 via a rotation angle of 20°20.

The pre-transfer static elimination lamp 16 uses a voltage supplied from a transfer drive source (not shown) to lower the potential of the toner of the developed toner image of the electrostatic latent image formed on the drum 7, thereby weakening its adhesion to the drum surface. The bias voltage applying means 17 is located on the lower surface side of the transfer sheet P, and is supplied with current from a transfer drive source (not shown) to increase the potential applied to the transfer sheet P, and prevents the transfer due to moisture absorption. It works to prevent current leakage to the seat.

Further, the transfer station 11 is supplied with voltage from the above-mentioned transfer drive source to increase the transfer efficiency when transferring the toner image on the drum 7 to the transfer sheet P.

Furthermore, the image forming apparatus of the embodiment includes the humidity sensor 1,
For example, it is placed near the transfer space B, and the voltage output from the humidity sensor 1 corresponding to the humidity is inputted to the control device 4 of the CPU 2 as shown in FIG. The calculation device 5 compares programs for controlling and driving the transfer device 11 and transfer auxiliary devices 16 and 17 according to various humidity conditions stored in advance, and outputs the calculation results to the control device 4 to perform the transfer. It is configured to control the means/transfer assisting means 6.

For example, if the CPU determines that the humidity is high, the transfer current is increased to improve the transfer efficiency, and a good image can be obtained even on paper that has absorbed moisture.

(2) At normal humidity, transfer conditions suitable for normal humidity can be obtained without changing the transfer current, and a good image can be formed.

■When the humidity is low, the transfer current is lowered so that avatar does not occur even on dry paper, and there is no excessive transfer and no peeling jam even on thin paper.

As described above, the drive sources of the transfer device and transfer auxiliary device are automatically and appropriately controlled based on the detection results of the humidity sensor, so the transfer operation can be performed automatically under optimal conditions. .

[Effects of the Invention] As is clear from the above description, according to the image forming apparatus according to the present invention, humidity change information detected by the humidity sensor is input to the CPU, and the CPU processes the humidity change information according to the input humidity change information. Since the operations of the transfer means and the transfer auxiliary means are appropriately controlled, a highly reliable and stable image can be automatically formed under any humidity environmental conditions.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the basic configuration of an image forming apparatus according to the present invention, and FIG. 2 is a main part showing the configuration of the image forming apparatus according to an embodiment of the present invention near the transfer means, drum, and transfer auxiliary means. 3 is a block diagram showing the connection relationship between the humidity sensor, CPU, and transfer drive source of the image forming apparatus according to the embodiment; FIG. 4 is a schematic configuration diagram of the conventional image forming apparatus; FIG. FIG. 2 is an explanatory diagram of the arrangement of a transfer device and a transfer auxiliary device in a conventional image forming apparatus. 1...Humidity sensor 2...CPU 3...Storage device 4...Control device 6...Transfer device means/transfer auxiliary means Fig. 1

Claims (1)

[Claims] The output voltage of a humidity sensor that generates a voltage according to humidity is input to the central processing unit, and the transfer means and transfer assistant of the image forming apparatus are activated based on the humidity versus transfer voltage information stored in advance in the central processing unit. An image forming apparatus characterized by controlling means.