JPS6250851A - Image forming device - Google Patents

Abstract

PURPOSE:To eliminate the adverse influence of rises in temperature of respective parts of a device and to hold picture quality excellent by detecting the temperatures of toner, a developer, and a photosensitive body and stopping image forming operation if >=1 of them are higher than a specific temperature. CONSTITUTION:A temperature sensor 111 provided on the bottom surface of a cleaning device detects the surface temperature of the photosensitive body, thermistors 113 and 115 provided at the upper and lower stages of a developing device detect the temperature of the developer, and thermistors 117 and 119 provided at the upper and lower stages of a toner hopper detect the temperature of the toner, so that their detection outputs are inputted to an input port 103. If >=1 of the detected temperatures are higher than the set temperature, a computer 101 judges that to stop an optical system driving circuit 105 and a conveyance system driving circuit 107 from operating, thereby controlling object equipment to lower than the set temperature. Thus, deterioration in picture quality due to a temperature rise is eliminated to maintain high picture quality.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an image forming apparatus, and particularly to a configuration for controlling the temperature of toner, developer, and photoreceptor.

[Technical background of the invention and its problems]

In general, in an image forming apparatus, various parts within the apparatus rise during the image forming operation, and as a result, images formed on paper, for example, often become inferior.

[Purpose of the invention]

This invention has been made in view of the above, and its purpose is to prevent the influence on the image due to temperature rise of various parts of the device accompanying the image forming operation, and to provide an image that can maintain good quality. An object of the present invention is to provide a forming device.

[Summary of the invention]

In order to achieve the above object, the image forming apparatus of the present invention includes: an image forming apparatus 5A that supplies toner to a developer and develops an electrostatic latent image on a photoreceptor with the developer; When it is detected that any one or more of the temperature detecting means of the agent and the photoreceptor, and the temperature detection target is higher than a predetermined constant temperature, the image forming operation is stopped and the temperature is adjusted to the predetermined constant temperature. It is characterized by having a temperature control means for lowering the temperature of the object to be detected whose temperature has exceeded the predetermined constant temperature.

(Embodiments of the invention) Hereinafter, embodiments of the invention will be described in detail based on the drawings.

FIG. 2 is a diagram showing the overall configuration of an image forming apparatus to which the present invention is applied.

In the figure, reference numeral 1 denotes a main body of the copying apparatus, and the upper part of the main body 1 of the copying apparatus is provided with an original placing glass 3 as an original placing part on which an original mA is placed, and a front edge of the upper surface. is provided with an operation panel (not shown).

Also, in the right side view of the copying apparatus main body 1, a paper feed cassette 5.
7.9 is installed. Further, the cassette cover 11 of the upper paper feed cassette 5 serves as a manual paper feed tray 13 for manually feeding paper P as appropriate. A drum-shaped photoreceptor 15 is arranged approximately in the center of the main body 1 of the copying apparatus.

A charging device 17. Exposure optical device 19° developing device 21. Transfer device 23. Peeling device 25.
A cleaning device 27 and an afterimage erasing device 29 are sequentially arranged.

In addition, paper feed cassettes 5.7.
Reference numeral 9 denotes a sheet P1 supplied from the automatic sheet feeder 31 or a sheet P manually fed from the manual sheet feed tray 13, through the image transfer section 33 between the photoreceptor 15 and the transfer device 23, and then transferred to the main body of the copying apparatus. The discharge section 35 provided in the left side view of 1
A paper conveyance path 37 is formed that leads to. Further, a pair of aligning rollers 39 is disposed on the upstream side of the image transfer section 33 of the paper conveyance path 37, and a fixing device 41 and a pair of paper discharge rollers 43 are disposed on the downstream side.

The exposure optical device 19 is surrounded at the back by a reflector 51, and includes an exposure lamp 53 as an exposure light source that irradiates light onto the document placement surface, and a reflection member that reflects light reflected from the document placement surface in a predetermined direction. a first optical unit 57 that has a first mirror 55 as a mirror and is movable along the document placement surface; A second mirror 61 that moves at half the speed and reflects the optical image reflected by the first optical unit 57 to the lens unit 59 side.
A second optical unit 65 having a third mirror 63 is provided.

At the rear of the unit 59 is a fourth mirror 67 as a reflecting member.
and a third optical unit 71 having a fifth mirror 69, and a sixth mirror 7 as a fixed reflecting member that reflects the optical image reflected by the third optical unit 71 toward the photoreceptor 15 side.
It has a configuration with 3. Note that 75 is a dustproof glass provided between the sixth mirror 73 and the photoreceptor 15, and 77 is a heat ray absorbing glass provided in front of the exposure lamp 53.

With the exposure lamp 53 turned on, the first optical unit 57 moves at a speed V along the document placement section, and in synchronization with this movement, the second optical unit 65 moves in the same direction. By moving at a speed of 1/2 of the speed V, the document A placed on the document placement surface is scanned and an image is formed on the photoreceptor 15 as an exposed portion which is rotating in advance. It has become. Then, an electrostatic latent image corresponding to the document A is formed on the photoreceptor 15, which is uniformly charged by the charging device 17.

The electrostatic latent image formed in this manner is developed by facing the developing device 21, and then sent to the image transfer section 33 facing the transfer device 23, and the developer image is passed through a pair of aligning rollers 39. The image is transferred onto the paper P that is fed in.

Next, the sheet P on which the image has been transferred is peeled off from the photoreceptor opening by the peeling device 25, and then guided through the conveyance path 37 to the fixing device 41 where the image is fixed.
3 and is discharged to the discharge section.

On the other hand, the surface of the photoreceptor 15 after the developer image has been transferred to the paper P is cleaned by facing the cleaning device 27.
The residual developer (toner) remaining on the photoreceptor 15 is cleaned off, and then the potential on the photoreceptor 15 is lowered to a certain level or less by the afterimage erasing device 29 to enable the next copying operation.

In this copying apparatus, the photoreceptor 15 is a drum equipped with selenium, and when the temperature of the photoreceptor 15 itself increases, the charge placed on the photoreceptor 15 by the charging device 17 tends to escape through the frame. The potential decreases. A decrease in the surface potential of the photoreceptor 15 directly appears as a decrease in image density.

Further, in the developing device 21, a developer is formed by carrier and toner. Toner usually melts due to heat, so as the temperature inside the developing device 21 increases, the toner in the developer becomes more likely to melt, forming a toner lump in the developer. The clumps of toner eventually fall onto the paper P due to reasons such as the underside of a natural image, and appear as stains on the copy.

Similarly, toner clumps are likely to occur in the toner hopper, which is the source of toner supply, due to temperature rise.

Note that, in FIG. 2, the toner hopper is not shown for convenience of drawing.

In order to eliminate the influence of the temperature rise of the toner, developer, and photoreceptor accompanying the image forming operation as described above, in one embodiment of the present invention, as shown in FIG. input boat 103;
Optical system drive circuit 105 and conveyance system drive circuit 10
7 and an operation panel 109.

An infrared temperature sensor 111 for detecting a temperature rise on the surface of the photoreceptor 15 is connected to the input port 103, and a thermistor 11 for detecting a temperature rise of the developer in the upper stage of the developing device 21 is connected to the input port 103.
3 and a temperature detection system including a thermistor 115 for detecting a temperature rise of the developer in the lower stage of the developing device 21, and a thermistor 115 for detecting a temperature rise of the toner in the upper stage of the toner hopper. 117 and a temperature detection system including a thermistor 119 for detecting a temperature rise of the toner in the lower stage of the toner hopper are connected to each other.

The mounting structure for each of these temperature rise detection elements is as shown in FIGS. 3, 4, and 5, respectively.

In other words, in FIG. 3, an infrared temperature sensor 11 is installed at the bottom of the cleaning device 27 in order to detect a temperature rise on the surface of the photoreceptor 15.
Figure 1 shows the structure in which 1 is attached. Note that FIG. 4A is a view of the cleaning device 27 as seen from the paper feeding side, and FIG.

FIG. 4 shows a mounting opening 2 formed in the lid 22 of the developing device 21 in order to detect the temperature rise of the developer in the upper stage of the developing device 21.
Insert thermistor 113 from 2a and connect this thermistor 1.
13 to the lid 22 and close the M22 with the thermistor 113 attached.
This shows a structure that can contain . Note that 22b is an auto toner sensor. Further, the illustration of the attachment of the thermistor 115 at the lower stage of the developing device 21 is omitted.

FIG. 5 shows that a thermistor 119 is installed from the mounting hole 24a formed at the bottom of the toner hopper 24 shown in FIG. The structure is shown in which the thermistor 119 is inserted into the hopper so as to pop out. Note that the illustration of the attachment of the thermistor 117 in the upper part of the toner hover 24 is omitted.

By attaching each temperature sensing element to each corresponding part in this way, each output from the temperature sensing system including these temperature sensing elements is applied to the microcomputer via the input port.

That is, a detection signal from the infrared temperature sensor 111 that detects the temperature on the surface of the photoreceptor 15 is processed in the unit to determine whether it is at a control level or not, and then is applied to the microcomputer 101 from the input boat 103.

Temperature detection signals from other narmistors are each processed by a comparator and applied to the microcomputer 101 from an input port 103.

Then, the microcomputer 101 checks each input signal and determines whether to continue or stop the image forming operation. Then, upon receiving a signal indicating that the image forming operation should be stopped, each operation of the optical system drive circuit and the transport system drive circuit is stopped, thereby stopping the image forming operation. At the same time, a display indicating the operation status of the main body, that is, the operation has stopped due to temperature rise, is displayed on the operation panel.

Furthermore, even after stopping the image forming operation as described above,
If only the photoreceptor 15 is rotated independently, the time for lowering the temperature of the photoreceptor 15 can be shortened.

Further, in the embodiment described above, an infrared sensor was used to detect the temperature on the surface of the photoconductor 15, and a thermistor was used to detect the temperature rise of the developer and toner. However, for example, a thermistor may be used in the non-image area of the surface of the photoreceptor, and the temperature of the developer and toner can also be sufficiently detected by a thermal lightning pair.

〔Effect of the invention〕

As explained above, in the image forming apparatus of the present invention, the image forming operation is stopped when one or more of the toner, the developer, and the photoreceptor reach a predetermined constant temperature or higher, thereby causing the temperature to rise. Since temperature control is performed to lower the temperature of the detection target to a predetermined constant temperature or less, it is possible to suppress a decrease in image quality due to a rise in temperature and maintain high image quality.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing the general configuration of the main parts of an image forming apparatus to which the present invention is applied, FIG. 2 is a diagram showing the overall configuration of the apparatus shown in FIG. 1, and FIG. FIG. 4 is an explanatory diagram of the mounting structure of a sensor for detecting the temperature rise of the developer, FIG. 5 is a diagram of the mounting structure of the thermistor that detects the temperature rise of the toner. 101...Microcomputer 103...Input boat 105...Optical system drive circuit 107...Transportation system drive circuit 109...Operation panel 111...Infrared temperature sensor 113.115, 117.119...・Thermistor (A
) (B) Figure 3

Claims (2)

[Claims] (1) In an image forming apparatus that supplies toner to a developer and develops an electrostatic latent image on a photoconductor with the developer, the temperature detection means for the toner, developer, and photoconductor; When it is detected that one or more of the detection targets is at a predetermined constant temperature or higher, the image forming operation is stopped and the temperature detection target whose temperature has reached the predetermined constant temperature or higher is set to the predetermined constant temperature. 1. An image forming apparatus comprising: a temperature control means for lowering the temperature. (2) The image forming apparatus according to claim (1), wherein the temperature control means includes means for forcibly cooling each of the temperature detection targets.