JPS6321662A - Image forming device - Google Patents

Abstract

PURPOSE:To preclude the partial deterioration of an image carrier and the trouble of an optical memory to a formed image and to prevent the image carrier from rotating more than required by providing a sensor and a controller and controlling the rotation of the image carrier. CONSTITUTION:Output signals from the light quantity sensor 6 and a temperature sensor 10 are inputted to a controller 22 and a fluorescent lamp 2, a driving motor 24, and a fixing heater 26 are controlled based on those inputs. Namely, when a fluorescent lamp wait-up sequence is entered, the fluorescent lamp 2 is turned on and a heater 26 also enters the wait-up sequence. Then when the fluorescent lamp 2 does not reach a specific quantity value, a drum 3 is rotated to a position where the exposed surface of the photosensitive drum (image carrier) is not exposed at set temperature lower than the fixation temperature of a fixing roller 9. Thus, the exposed surface of the drum 3 is displaced to prevent the same part from being irradiated by the fluorescent lamp 2 for a long time, and consequently the partial deterioration of the drum 3 and the trouble of the optical memory to the formed image are precluded and the drum 3 is prevented from rotating more than required.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention exposes a document to light using a light source such as a fluorescent lamp,
The present invention relates to an image forming apparatus that forms a latent image on an endless image carrier using reflected light from the document, develops the latent image to form an image, and fixes the formed image with a fixing roller.

(Prior Art) Conventionally, image forming apparatuses that use fluorescent lamps as document exposure light sources have had to install a heater near the tube surface of the fluorescent lamps, or Alternatively, a fluorescent lamp is controlled to emit a predetermined amount of light using its own heat by continuously lighting it.

(Problems to be Solved by the Invention) However, in the former case in such a conventional example, a heater must be provided, which requires space for installing the heater and increases costs.

There is a problem of increased power consumption, which is not practical for portable types and battery-powered types in particular, and in the latter case, the photoreceptor as an image carrier is exposed to light while the fluorescent lamp is turned on. As a result, only that portion becomes an optical memory, and the deterioration of a portion of the photoreceptor progresses and the deterioration is not uniform, resulting in problems in image formation.

As a means to solve this problem, conventional methods have been devised to rotate the mass photoreceptor that lights the fluorescent lamp, but this method increases the amount of drive energy consumed, especially for battery-powered types. is inappropriate. Further, in a device provided with a counter for displaying the amount of remaining toner, there is a problem in that the counter continues to advance even though image formation is not in progress and toner is not consumed.

Therefore, the present invention has been made to solve the above-mentioned problems of the conventional example, and its purpose is to prevent partial deterioration of the image bearing member, prevent optical memory, and furthermore, prevent the image bearing member from deteriorating partially. An object of the present invention is to provide an image forming apparatus which prevents the image forming apparatus from rotating more than necessary.

(Means for Solving the Problems) In order to achieve the above object, in the present invention, an original is exposed to light using a light source, and a latent image is formed on an endless image carrier by light reflected from the original. In an image forming apparatus that forms a latent image, develops this latent image to form an image, and fixes the formed image with a fixing roller, the light source continues to be turned on and image formation is enabled when a predetermined light amount value is reached, and the fixing roller When the temperature of the roller is lower than the fixing temperature and the light source is continuously lit, the image carrier rotates so as not to expose the same position.

(Function) In the present invention having the above configuration, image formation is enabled when the light source continues to be turned on and reaches a predetermined light amount value, and when the temperature of the fixing roller is lower than the fixing temperature, the light source is continuously turned on. When the light is on, the image carrier is rotated so as not to expose the same position, thereby preventing a portion of the image carrier from being exposed.

(Example) The present invention will be explained below based on the illustrated example. 1st
The figure is a schematic configuration diagram showing an embodiment of an electrophotographic copying machine to which the present invention is applied. In the figure, numeral 3 denotes a photoreceptor drum as an endless image carrier rotatable in the direction of the arrow; After the photosensitive drum 3 is uniformly charged by the primary charger 11, it is exposed to image light. That is, an original (not shown) placed on an original platen 1 is illuminated by a fluorescent lamp 2 serving as an image exposure light source, and the photoreceptor drum 3 is exposed to the reflected light. An electrostatic latent image is formed on the surface of the photosensitive drum 3 by image exposure, and the electrostatic latent image is developed with toner from a developing device 4 . The toner image on the photoreceptor drum 3 is transferred by the transfer charger 7 onto the transfer material transported by the paper feed roller 8, and then separated from the photoreceptor drum 3, and the toner image is fixed by the fixing roller 9. It will be established.

Further, 5 is a cleaner for removing toner remaining on the photosensitive drum 3, 6 is a light amount sensor for detecting the light amount of the fluorescent lamp 2, and 10 is a temperature sensor for detecting the temperature of the fixing roller 9.

FIG. 2 is a block diagram of the control system shown in FIG. 1, in which 21 is a fluorescent lamp driver for lighting the fluorescent lamp 2, 22 is a controller having a microcomputer,
23 is an operation unit that sends operation signals to the controller 22;
24 is a drive motor for driving the photosensitive drum 3;
6 is a fixing heater provided in the fixing roller 9, and 25 is a heater driver for lighting the fixing heater 26. In the above configuration, the output signal from the light amount sensor 6 is input to the controller 22, and the output signal from the temperature sensor 10 is also input to the controller 22, and the controller 22 controls the fluorescent lamp based on the flow chart shown in FIG. 2
．． Drive motor 24 and fixing heater 26 are controlled.

That is, FIG. 3 is a flowchart of this embodiment, and when the fluorescent lamp weight-up sequence is reached, step
At this time, the fluorescent lamp 2 is turned on, and at the same time, the fixing heater 2 is turned on.
6 is also a wait-up sequence. Next, in step (2), it is determined whether or not the fluorescent lamp 2 has a predetermined light amount value, and if it has the predetermined light amount value, the wait is increased. On the other hand, if the fluorescent lamp 2 does not have a predetermined light intensity value in step (2), it is determined in step (2) whether or not the second set temperature is lower than the fixing possible temperature of the fixing roller 9, and the second set temperature is reached. Then, in step (2), the photosensitive drum 3 is rotated to a position where the exposed surface of the photosensitive drum 3 is not exposed. This rotation angle is the angle α in FIG. 1, and in order to prevent the same part of the photoreceptor drum 3 from being irradiated with the light of the fluorescent lamp 2 for a long time, it is preferable that this angle α is not an integral multiple of 3600. desirable.

Thus, in this embodiment, when the temperature of the fixing roller 9 reaches the second set value lower than the fixable temperature, the photoreceptor is moved so that the exposed surface of the photoreceptor drum 3 is displaced when the fluorescent lamp 2 is continuously lit. It controls the rotation of the drum 3.

In the above control system, if the fixing roller 9 is sufficiently warmed, it is considered that the fluorescent lamp 2 is also sufficiently warmed, so by setting the second set temperature to a temperature at which the fluorescent lamp 2 is not completely cooled, The above control becomes effective.

In the above embodiment, a fluorescent lamp is used as the image exposure light source, but the present invention is not limited to this, and a halogen lamp or the like may be used.

(Effects of the Invention) The image forming apparatus according to the present invention has the above-described structure and operation, and can prevent partial deterioration of the image bearing member and prevent defects in the image formed by the optical memory. Since the body does not rotate, it saves energy and prevents unnecessary counter movement when the counter is attached. Also, since there is no need to install a heater near the light source,
Eliminates the need for installation space for the heater, reduces costs,
This has the effect of reducing power consumption.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing an embodiment of an electrophotographic copying machine to which the present invention is applied, FIG. 2 is a block diagram of the control system of FIG. 1, and FIG. 3 is a flowchart of the same embodiment. Explanation of symbols 2... Fluorescent lamp (light source) 3... Photosensitive drum (image carrier) 6... Light amount sensor 9... Fixing roller 10...
・Temperature sensor 22... Controller 24... Drive motor 2122 9 Figure 2 Figure 3

Claims (1)

[Claims] An image in which a document is exposed to light from a light source, a latent image is formed on an endless image carrier by light reflected from the document, this latent image is developed to form an image, and the formed image is fixed by a fixing roller. In the forming apparatus, when the light source continues to be turned on and a predetermined light amount value is reached, image formation is enabled, and when the temperature of the fixing roller is lower than the fixing temperature and the light source is continuously turned on, the image bearing An image forming apparatus characterized in that the body rotates so as not to expose the same position.