JPS626275A - Exposing device - Google Patents

Abstract

PURPOSE:To prolong the life of a fluorescent lamp by detecting the quantity of light of the fluorescent lamp in warming-up operation and turning off the fluorescent lamp when the detected quantity of light reaches a specific value. CONSTITUTION:When the temperature of the tube wall of the fluorescent lamp rises, the quantity of light emitted by the fluorescent tube through an aperture part also increases. When the quantity of light exceeds a reference value L0, a light quantity detection sensor 31 informs a fluorescent lamp turn-on control circuit 32 of that. On knowing that the quantity of light exceeds the reference value L0, the fluorescent lamp turn-on control circuit 32 stops feeding electricity to the fluorescent lamp 20. Simultaneously, a fixing heater generates heat and when a state wherein fixation is possible is entered, a ready lamp illuminates to inducate that copying operation is possible. When a copy button is pressed, the fluorescent lamp turn-on control circuit 32 starts powering on the fluorescent lamp 20 again to perform the copying operation.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention efficiently controls the lighting of a fluorescent lamp used in an image forming apparatus equipped with an exposure device such as an electronic copying machine or used simultaneously with an exposure device. The present invention relates to an exposure apparatus adapted to perform such exposure.

(Prior Art) An electronic copying machine exposes a charged drum to light in accordance with document information, and then forms a toner visible image on an electrostatic latent image formed on the drum surface. This is a device that transfers images onto copy paper.

FIG. 2 is a diagram showing an example of the conventional configuration of such an electronic copying machine. When the operator presses a copy start button (not shown), the illustrated device begins a copy operation. The photosensitive drum 1, which is rotating in the direction of the arrow, is cleaned by a blade in the cleaning section 2, after which the remaining toner on the photosensitive drum is scraped off by a blade, and then corona discharge is applied to the photosensitive drum 1 by the charged electrode 3, so that ten poles of electric charge are applied to the entire surface of the photosensitive drum 1. Becomes electrically charged. An unnecessary portion of the charge charged by the charging electrode 3 is erased by a charge eraser 4.

On the other hand, light is irradiated from the exposure unit 6, which is controlled on and off by the fluorescent lamp lighting circuit 5, to the document 8 placed on the document table 7, and the reflected light, which is light according to the document information, is transmitted to the optical transmission device. The light is focused by a SELFOC lens (manufactured by Nippon Sheet Glass Co., Ltd.) 9, which is an example of the above, and is irradiated onto the photosensitive drum 1. here,
When the document table 7 is horizontally moved in the direction of the arrow in the figure, the image information on the document 8 is focused by the SELFOC lens 9 and sequentially irradiated onto the photosensitive drum 1. As a result, a static N latent image of the document image information is sequentially formed on the surface of the photosensitive drum, from which unnecessary portions outside the required image area have been charged and erased by the charge erasing section 4. In this case, the charge erasing section 4 is connected to the broken line 4 in FIG.
As shown in '', it may be arranged downstream of the imagewise exposure from the exposure device (Selfoc lens) so that as the imagewise exposure is completed, the charges in unnecessary portions are erased.

The electrostatic latent image formed on the surface of the photosensitive drum 1 is converted into a visible image by adsorption of toner in the subsequent developing section 10.

The toner image on the surface of the photosensitive drum is transferred to a copy paper in a transfer section 11, and the copy paper that is in close contact with the photosensitive drum 1 is separated. The separated copy paper is sent via the conveyance mechanism 12 to a fixing roller 13, which is a fixing device, and the copy paper is heated and pressurized by the fixing roller 13, so that the toner on the copy paper is fused to the copy paper. , the copy operation ends.

Incidentally, as the light source 20 used in the exposure section 6, for example, a fluorescent lamp as shown in FIG. 3 is used. In FIG. 3, (a) is a perspective view, and (b) is a sectional view taken along the line AA'. In the figure, 21 is a bottle, 22 is a cap, and 23
2 is a heater formed surrounding the fluorescent tube 24, and 25 is a heat generating portion of the heater 23. 26.27 is an electrode for applying current to the heater 23, and 28 is a reflection! l cum fluorescent discipline, 2
9 is an opening (aperture part). The heater 23 is the tube W of the fluorescent tube 24! To raise the hot water temperature quickly, or pipe!
! It is provided to maintain the temperature at a desired temperature.

The relationship between the moisture content of the tube wall and the amount of emitted light of a fluorescent lamp constructed in this manner is shown in FIG. 4. In the figure, the horizontal axis shows the fluorescent tube wall concentration, and the vertical axis shows the amount of emitted light. The tube wall temperature of the fluorescent lamp reaches a predetermined reference value (j in the figure) within the warm-up time of the fixing heater provided in the fixing roller 13.
If o> is not reached, there will be a lack of light. The amount of light emitted at a temperature to is Lo, and if the tube wall temperature of the fluorescent lamp does not rise above to within the warm-up time, the amount of light will fall below Lo, resulting in insufficient light, making it impossible to copy an accurate image. .

(Problem to be Solved by the Invention) In order to compensate for the lack of light intensity of the fluorescent lamp described above, conventionally, a fluorescent lamp is always turned on when the fixing roller is warmed up, and the rise in tube wall moisture is accelerated, and the fixing roller is heated up. By the time the warm-up is complete, the tube! The temperature was set to be equal to or higher than the reference value to. In such a conventional system, the fluorescent lamp is always turned on while the fixing roller is warmed up, which shortens the life of the fluorescent lamp.

The present invention has been made in view of these points, and
The purpose is to realize an exposure apparatus that can extend the life of a fluorescent lamp.

(Means for Solving the Problems) The present invention, which solves the above-mentioned problems, illuminates the surface of a document with a fluorescent lamp, and uses light corresponding to the document information or a signal based on the light as an optical signal to be exposed to light. An exposure device used in an image forming apparatus that irradiates the body to form a static N latent image, develops the electrostatic latent image, adheres toner to copy paper, and fixes it as an image through a fixing device. The present invention is characterized in that the amount of light from the fluorescent lamp is detected at certain times, and when the amount of light reaches a predetermined value, the lighting of the fluorescent lamp is turned off.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention.

Components that are the same as those in FIG. 2 are designated by the same numbers.

In the figure, 31 is a light amount detection sensor that detects the amount of light emitted from the fluorescent lamp 20, and 32 is a fluorescent lamp lighting control circuit that receives the output of the light amount detection sensor 31 and controls the on/off of energization to the fluorescent lamp 20. be. The fluorescent lamp lighting control circuit 32 stores in advance a reference value Lo for turning off the energization when the amount of light increases. The operation of the apparatus configured as described above is as follows.When the electronic copying machine is turned on, first the fixing roller 13
A fixing heater (not shown) in the i! Electricity is started to be applied to the light lamp 20 and the heater 23 (see FIG. 3) of the fluorescent lamp.

As a result, the tube wall of the fluorescent lamp gradually rises due to self-heating due to the energization and heat generation from the heat generating portion 25 due to the energization of the heater 23. As the temperature of the tube wall increases, the amount of light emitted from the fluorescent tube through the aperture section 29 also increases accordingly, as shown in FIG. Then, when the light amount exceeds the reference value Lo, the light amount detection sensor 31 notifies the fluorescent lamp lighting control circuit 32 to that effect. Fluorescent lamp lighting control circuit 32
The light amount is set to the reference value L based on the output of the light amount detection sensor 31.
When the fluorescent lamp 20 is found to have exceeded 0, power to the fluorescent lamp 20 is stopped.

Meanwhile, during this time, the fixing heater also generates heat and becomes ready for fixing. When fixing is possible, the READY lamp of the electronic copying machine lights up to notify the operator that copying is possible.

When the operator presses the copy button, the fluorescent light lighting control circuit 3
2 starts energizing the fluorescent lamp 20 again and performs the copying operation in the manner described with reference to FIG.

Note that during the copying operation, the amount of light emitted from the fluorescent lamp 20 is controlled to be constant. Once the power supply to the fluorescent lamp 20 is stopped, the temperature of the wall of the fluorescent lamp tube hardly decreases and is approximately t because the external heater 23 is constantly energized.
o is maintained. Therefore, when the operator presses the copy button and energization of the fluorescent lamp 20 is started, the amount of emitted light quickly reaches the reference value Lo, providing a sufficient amount of light.

As described above, according to the present invention, it is possible to minimize the lighting time of the Q fluorescent lamp during warm-up of the fixing roller, thereby significantly extending the life of the fluorescent lamp. For example, when the ambient temperature of the fluorescent lamp is high (close to to in FIG. 4), it is not necessary to turn on the fluorescent lamp most of the time. Therefore, power consumption can also be kept low.

In the above explanation, an example was explained in which, when the light intensity of the fluorescent lamp exceeds the reference value Lo after the power is turned on, the power to the fluorescent lamp is stopped and the lamp is left as it is, but the present invention is not limited to this. For example, once the power to the fluorescent lamp is stopped, once the tube wall temperature drops to a certain value, so-called on/off control is performed to restart the power to the fluorescent lamp, and the fixing roller is brought into a ready state. You may also have one. Such a method is particularly effective when the electronic copier is located in a room that is not temperature controlled (especially during the winter).

Further, in the above explanation, the case where the power supply to the fluorescent lamp is stopped when the light intensity of the fluorescent lamp reaches a predetermined value is explained as an example, but the present invention is not limited to this, and the present invention is not limited to this. The same effect can be obtained by setting the tube wall temperature to a certain value and stopping the energization when the tube wall temperature reaches this certain value. That is, the energization may be stopped when the tube wall temperature reaches the above-mentioned to. Also, the above is
As an electronic copying device, we have described a copying device that exposes light reflected from an original through an optical system, but the invention is not limited to this. Of course, digital copying devices are also included.

(Effects of the Invention) As described in detail above, according to the present invention, after the power is turned on, when the amount of light emitted from the fluorescent lamp reaches a predetermined reference value, the power to the fluorescent lamp is stopped, can significantly extend the lifespan of.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a diagram showing an example of the conventional structure of an electronic copying machine, Fig. 3 is a diagram showing an example of the structure of a fluorescent lamp, and Fig. 4 is a diagram showing an example of the structure of a fluorescent lamp. FIG. 3 is a diagram showing light emission characteristics. 1... Photosensitive drum 2... Cleaning section 3.
... Charged electrode 4 ... Charge erasing section 5 ... Fluorescent lamp lighting circuit 6 ... Exposure section 7 ... Document table
8... Original 9... SELFOC lens 10... Developing section 11... Transfer section 12...
Conveyance mechanism 13...Fixing roller 20...Fluorescent lamp 31...Light level detection sensor 32...Fluorescent lamp lighting control circuit Patent applicant Roku Konishi Photo Industry Co., Ltd. Representative Patent attorney Fuji Ijima Harukai 1 person Figure 3 (a) 25, f@HB 27, electric polishing terminal 28, reflective film/fluorescent film 29; 7/<-h"(+t'!o") (.) Fluorescence 11 Uniformity

Claims (1)

[Claims] The document surface is irradiated with a fluorescent lamp, and a photoreceptor is irradiated with light corresponding to the document information or a signal based on the light as an optical signal to form an electrostatic latent image, and the electrostatic latent image is developed. An exposure device used in an image forming device that attaches toner to copy paper and fixes it as an image through a fixing device,
An exposure apparatus characterized in that the light intensity of the fluorescent lamp is detected during warm-up, and when the light intensity reaches a predetermined value, the lighting of the fluorescent lamp is turned off.