JPS5818669A - Method and device for controlling luminous intensity of fluorescent lamp for copying machine - Google Patents

Abstract

PURPOSE:To control a light source for discharging a photoreceptor to successively specified luminous intensity, by controlling a cold cathode type fluorescent lamp for electrostatic charge removal according to detected ambient temperature. CONSTITUTION:A light source for discharging a photoreceptor is formed of a cold cathode type fluorescent lamp 60, and the ambient temperature at the center part, etc., of the fluorescent lamp 6 is detected by the thermistor 661, etc., of a luminance intensity control circuit 66. A turn-on current to the LED of a photocoupler 663 is adjusted by the output of a circuit part 661 which corresponds to the detected temperature corresponding to the luminous intensity of the fluorescent lamp 60 proportional linearly to the supply current to control the current applied to the fluorescent lamp 60, and consequently the luminous intensity of the fluorescent lamp 60 is controlled to a successively specified value even in case of deterioration, thereby performing the discharging of the photoreceptor stably and uniformly for a long period.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is an electrostatic copying apparatus (hereinafter referred to as a copying machine) using a photoconductive photoreceptor (hereinafter referred to as photoreceptor), and is used to remove static charges on the surface of the photoreceptor. Concerning the control of the luminous intensity of fluorescent lamps.

Using a photoconductor, a photoconductor is used to uniformly apply an electrostatic charge to the surface of the photoconductor, and then imagewise exposure is applied to remove the static charge in an imagewise manner to form a static charge.

developing the electrostatic latent image to form a toner image on the surface of the photoreceptor;
Next, transfer the wrinkled toner image to a transfer material such as transfer paper, j! The purpose of copying is achieved by fixing on the image.

The copying machine part related to the 1st rlJK main beak is shown. 10 is a photoreceptor (exemplified as a drum), a charger such as 101Fi corona discharge, 102 is an optical exposure device for forming an electrostatic latent image, 103 is an atomizer for generating a toner image, and a P. Paper feed E'-7, 10 that supplies the transfer paper placed on the paper holder, 10411 transfer paper, to the top surface of the photoreceptor! S is a transfer separation electrode that transfers the toner image to the transfer paper t and separates the transfer paper Pil to which the toner image has been transferred from the photoconductor to-111 surface; This is a cleaner that removes residual snow toner. In order to obtain a good image, the reverberant static charge is removed using 1111-7, and generally the surface of the photoreceptor 10 is exposed to light using photoconductivity.
(hereinafter referred to as photostatic charge removal), the purpose of optical charge removal is to maintain an electrostatically uniform photoconductor 10 prior to charging by the charger 101. It is also used to remove static charges outside the original area, or to remove static charges other than excess toner images before transfer.

In FIG. 1, reference numeral 11 is a photostatic charge removal @ located in front of the charger 101 to remove static charges on the surface of the photoreceptor 10H or to equalize the degree of fatigue of the photoreceptor 10, and 12 is the time when the optical system is returned. ,
In addition, toner that is not used for copying is transferred to the surface of the photoreceptor 10 by charging the outside of the document area and removing the static charge at the time of reduction/copying. This is a partial exposure device to prevent the material from sticking to the surface and being removed and wasted. Also, 13 is iAg#510
3 and the transfer separation electrode 1050 is a round pre-transfer exposure device that adjusts the amount of electrostatic charge on the surface of the photoreceptor 10 and improves the transfer rate of the toner image and the separation rate of the transfer paper.

The light sources for the above-mentioned optical static eliminator, 111 partial exposure device 12$1-, and pre-transfer exposure device 13 may be an incandescent light bulb made by Hakuoh-Hatsu of 719 Ment, a Light Eighting Diode (C, L, D), or a light lamp. etc. are used.

Among these light sources, incandescent bulbs and Y■ require multiple areas to be lined up in order to irradiate the required area, resulting in uneven luminous intensity distribution, causing uneven photostatic removal and uneven photo fatigue during exposure. It has disadvantages such as raw sludge. We met′*thermal heating wire,
There is a danger that the high heat generated may cause deterioration of the photoreceptor.

-1 Fluorescent lamp is an excellent optical static elimination light source in that it does not have the above-mentioned nine drawbacks. However, the vapor pressure of the water and silver sealed inside the tube changes dramatically depending on the temperature INK, so the temperature inside the tube is l!
The emitted light f strongly depends on. The situation is shown in Figure 2. The vertical axis is the relative luminous intensity with the expansion tube wall temperature set at 100°C, and the horizontal axis is the temperature. However, the temperature is the tube internal temperature Kf! A tube wall temperature proportional to V was used.

11KII indicates the relative luminosity between θ°C and φ°C.

The temperature inside the tube of a universal lamp is 1', the installation location is 11III, the temperature inside the tube is 1', the installation location is 11III, the circumferential temperature of a standard fluorescent lamp is 9, and although it generates less heat than a blind self-heating bulb, its own discharge current is large. It fluctuates due to the rise in the temperature inside the pipe due to the heat generated.

When a fluorescent lamp is used as a light source for optical static elimination, disadvantages such as fogging, reduced toner transfer efficiency, or separation of transfer paper (so-called jamming) often occur when the temperature inside the tube of a solar light lamp is low. Due to the heat generated by the discharge current, the situation varies depending on the lighting time.

However, as mentioned above, the final determination of the luminous intensity of the large wall lamp is IgIllF
Cold cathode wall lamps (hereinafter referred to as lou electric lamps) are a convenient option. There is a linear relationship between the lamp current and the relative luminous intensity of this electric lamp. In FIG. 4, Km can be easily rounded by changing the output of the secondary equipment and the resistance R of the luminance δ for a lamp current of 5 mm.

1. In addition, the Lou electric light can be turned on instantly, has a smaller volume of about H than the Tatami-dori fluorescent light, and is inexpensive because it does not require a lighting auxiliary device.

The electric light and the surrounding circuit are shown in Figure 11
The title is Lou electric lamp, 21 is a cold cathode fluorescent tube, 2
2 and 22I are electrodes provided at both ends of the fluorescent tube B, and Tadaru' is a cap. 24 is called a proximity conductor, and in the example shown in Figure 1, it extends along the outer wall (atmospheric side) K of the fluorescent tube 4 from the i side electrode n to the other electrode n'. This is a conductive coating film attached close to the electrode 22' without contacting it. 2 is the current to the lou electric light 20 4#
Battle Sai transformer B is an AM stake inserted between transformer B and cold cathode lamp to control nine electric power 5i11.

K AC between electrode n and 22I: 300 to 700 V
When chisel pressure is applied, a discharge phenomenon occurs between the nearby conductor and the nearby electric wire 22I, which triggers a continuous discharge between electrodes n and 4', which lights up. be done. The lamp current required for the above-mentioned continuous discharge is 1~IQ mA, which is significantly smaller than the two-knob current of several hundreds of mA for a normal fluorescent lamp, so self-heating due to the lamp current is almost ignored. , the temperature of the fluorescent tube 4 is almost equal to the ambient temperature.

As mentioned above, electric lamps have many advantages over ordinary fluorescent lamps, but since the principle of light emission is the same as that of ordinary fluorescent lamps, the luminous intensity depends on the temperature as shown in Figure 2. It is the same as shown in . However, in the light lamp, the self-heating effect is almost ignored and the relative luminous intensity is almost proportional to the lamp current, so the lamp current must be controlled to avoid the light disturbance of the wrinkled wall lamp. The amount of light irradiated onto the photoconductor from the optical static eliminator 111 partial exposure device 12, the pre-transfer exposure device 13, etc. must be suppressed within a practical allowable range. However, there has been no proposal to continuously maintain the luminous intensity of the light source or the amount of irradiated light within a certain range, which is involved in optical static elimination.

Another object of the present invention is to provide a method for continuously keeping the luminous intensity constant (a predetermined luminous intensity), and further to provide a device for continuously keeping the luminous intensity constant based on the method. - The object of the present invention described above is to use a cold cathode fluorescent lamp to remove static charge from the surface of a photoconductive photoreceptor in a copying machine that uses a photoconductive photoreceptor, and to remove the static charge from the surface of the photoconductive photoreceptor. The first sensor detects the temperature, and the detection output of the first sensor is human-powered.

1. A method for controlling the luminous intensity of a fluorescent lamp for copying scissors, the method comprising: a second step of controlling the two-amp current of the cold cathode crinkled wall lamp; Photography device KTh
In order to remove static charge from the surface of the photoconductive photoreceptor, a cold cathode cover wall light is used. output as human power.

This can be achieved by a luminous intensity control device for a double JI installation fluorescent lamp which is connected to a lamp current control means for controlling the lamp current of the cold cathode cover wall lamp.

(9) A preferred embodiment of the light intensity control device is as follows:
The lamp is configured such that a predetermined luminous intensity and a lamp current for producing the luminous intensity correspond to each other.

*Also, the detection output of the temperature detection means when the lamp has a predetermined luminous intensity is used as a reference output, and this is used as the reference human power of the lamp current control means.

The present invention is now illustrated as a block diagram in FIG.

In the figure, 56A means a system for implementing the luminous intensity control method of the present invention, and 56A indicates a system for implementing the luminous intensity control method of the present invention. In the process, 56B compares the output of the first process (arrow bK phase!!&) with a predetermined light intensity (voltage corresponding to light Il!, etc.) to control the lamp current of the cold cathode lamp group (
Arrow cK111) This is the second process. 57 and 5611 are input terminals for adjusting the first overload and the second overload 5611 from the outside.

First, in the first step, the ambient temperature of the Lou electric lamp ω when the Lou electric lamp ■ is at the appropriate light intensity, that is, the luminous intensity suitable for removing static charges on the photoreceptor, etc., is manually determined, and the output at that time is used as the reference value. 2 over 1! In the second step, the lamp current is adjusted based on the input from the first step so that the lamp has an appropriate luminous intensity. Adjustment of the appropriate lamp current for the appropriate luminous intensity is the second process, and the ambient temperature that affects it changes, which requires less manpower for the first process. Therefore, the manual effort from the first process to the second process is reduced, and in the second process, the nine inputs that change ore are compared with the reference value corresponding to the appropriate luminous intensity, and the amount of displacement is fed back to the lamp current. It works like this.

Similarly, it can be explained using the same diagram as diagram 5 of the wiring diagram of the light intensity control device having the temperature detection means of the present invention.

In FIG. 5, numeral 56 represents a cold cathode lamp, and numeral 56 represents a light intensity control device of the present invention. 56B is lamp current control means. Cold cathode breakthrough and luminous intensity control device 56 Minebetsu electric power 11 [K operates by means of temperature detection means, which detects the ambient temperature of the cold cathode breakthrough and light intensity control device (see the arrow ■), detects the appropriate size of electricity as a result of the detection. It is converted into a signal and manually inputted to the lamp current control means 56B (corresponding to the OK arrow). 2 lamp current control means rABFi The magnitude of the force, the direction of control (promote or suppress the light), control the resistance and voltage of the cold cathode lamp (corresponding to the arrow OK), reduce and maintain the lamp current or increase, controlling the luminous intensity of the light of the cold cathode lamp, which is linearly related to the two-amp current.

1 As explained in FIG. 2, the luminous intensity emitted by the cold cathode breakthrough strongly depends on the temperature inside the fluorescent tube, and in the cold cathode breakthrough, there is almost no self-heating due to the discharge current, and the luminous intensity generated by the cold cathode breakthrough strongly depends on the temperature inside the fluorescent tube and the fluorescent tube. By taking advantage of the fact that the light tube wall temperature is almost equal to the ambient temperature, the ambient temperature is used as an index of the luminous intensity emitted by the cold cathode lamp.

The temperature detecting means includes a temperature detecting element that detects the ambient temperature of the cold cathode mark, a circuit and an auxiliary circuit that converts the electrical output generated by the temperature detecting element into a value of an appropriate size. In this example, a thermistor was used as the temperature sensing element, but other types such as thermocouples and ceramics can also be used. Temperature sensors, diode temperature sensors, transistors, temperature sensors, etc. can be used.

As mentioned above, the temperature sensing element according to the present invention
Mli! Since it is sufficient to detect the I temperature, it may be a contact type or a non-contact type for the detection target, and the temperature sensor of another temperature specimen (for example, a photoreceptor, etc.) according to the present invention can be used for temperature detection. It can also be used in common as an element.

The circuit KFi and various circuits used in the fi & detection means 56AK can be used. For example, as shown in Figure 6, this can be achieved by detecting changes in the ambient temperature of the cold cathode lamp as changes in resistance using a thermistor. The resistance lamp current control means 56B adjusts the resistance or voltage of the operating power supply circuit of the cold cathode lamp according to the output from the wrinkle means, and controls the luminous intensity by increasing or decreasing the lamp current. Incorporate a photocoupler or transformer current control circuit inside to control the rung current of the cold cathode lamp. ΦGood.

In the temperature detecting element of the temperature detecting means 56A, the electrical signal generated by manual temperature control from around the valuable lamp is adjusted to an appropriate size KWI4, outputted as a detection output from 56A, and then manually input to the lamp current control means 56B. , when the output is for the lamp current control of cold cathode breakthrough, the temperature sensing element incorporated in both means, etc. → control element, circuit combination K. Accordingly, the operating direction of the lamp current control means 56B is determined for control purposes. A switching circuit is installed between the luminous intensity control devices so that the lamp current increases when the luminous intensity of the cold cathode marking decreases, and decreases when the luminous intensity increases.

When carrying out the light intensity control method of the present invention and putting the light intensity control device into practical use, the light source such as the optical static eliminator, partial exposure device or pre-transfer exposure device is most preferable, that is, static electricity is removed as specified. It is necessary to adjust the luminous intensity to a predetermined value that can be used. That is, there are variations in the performance of cold cathode lamps, photoreceptors, and the light intensity control device of the present invention, and these variations vary depending on the degree of use and period of use.

In the present invention, the temperature detection means 56 is used to set a predetermined luminous intensity while comprehensively eliminating variations in the various performances.
Section AI111 refers to the lamp current control means 56.
If you increase or decrease the resistance (not shown) of the circuit between m or adjust the comparison control circuit in 56B, then K.
The lamp current control means 56B operates to generate a predetermined luminous intensity in the lamp electric lamp 111 (abbreviated as specified current).
can be energized.

91 In the present invention, in order to maintain the predetermined luminous intensity in response to the displacement of the output of the predetermined light fK compatibility detection means,
The lamp current control means can increase or decrease the lamp current. For example, the present invention will now be described with reference to Examples. In Figure 6, a thermistor is used as the ambient temperature detection element of the electric light, and an LED is used as the 2-amp current control means.
This is an example of the present invention using a photocoupler made of cadmium sulfide and cadmium sulfide.

In Figure 6, the sob cold shade lamp is a transformer.

This is a holding resistor installed in the circuit between the lFi fluorescent tube ω and the transformer section. 66 is a light intensity control device of the present invention, and 641 is a circuit unit for increasing/decreasing, comparing, adjusting, etc.

663 is a photocoupler consisting of an LID and a cadmium sulfide cell, and the cadmium sulfide cell serves as a circuit resistance for the electric lamp ω, and receives the source from the LED to change the resistance and change the lamp current. r is a variable resistor corresponding to a predetermined luminous intensity, and when the output 0t)T of the circuit 662 is constant,
The current of the photocoupler 663 to the LED is adjusted, and the system of the luminous intensity control device is set so that it becomes a specified current that provides the luminous intensity.

The light intensity control device 6 and the thermistor 661 are installed at a position that does not interfere with the projection of the light ω onto the surface of a photoreceptor (not shown). Of course, the thermistor 661 is preferably installed near the tube wall near the center of the cold cathode button. For example, if the lamp current decreases from the specified current due to power supply fluctuations, etc.9
, when the luminous intensity falls from a predetermined luminous intensity due to deterioration of the lou electric lamp ω, the temperature of the tube wall of the lou electric lamp ω also decreases, and the thermistor 66
The resistance value of 1 increases. This change causes the output OUT to decrease via the circuit section 662. As a result, the lighting current of the LED of 7 Otocap J-663 increases, increasing its luminous intensity, which reduces the resistance of the cadmium sulfide cell of the photocoupler 663, which forms the circuit resistance of the light bulb, and increases the lamp current. The luminous intensity is increased to control the luminous intensity to a predetermined (appropriate) level.

If the lamp current of the lamp increases beyond the specified current, or if the amount of light from the lamp increases due to a change in ambient temperature, the operation is the opposite of the above.

FIG. 7 shows an embodiment of the light intensity control device group, which is a break from the Kga diagram. 76 is a light intensity control device, and 761 is a thermistor that is part of a %7g8U photocoupler.

If the luminous intensity of the electric lamp decreases due to some reason such as a decrease in temperature, and the amount of light decreases, the resistance value of the thermistor of the temperature detection element installed in the vicinity increases, so the VA
The voltage rises and the input terminal to the inverting amplifier circuit using an operational amplifier OP or the like rises.

As a result, the VB voltage drops, and the L of the photocoupler 763
Increase the current to ID 7631. Then, it was explained that the resistance of the Cd8 cell 7632 included in the energizing circuit of the Lou electric lamp is reduced, thereby increasing the lamp vL current, increasing the luminous intensity of the Lou electric lamp, and maintaining a predetermined light amount, but of course, this is limited to the above embodiment. Various light receiving elements,
The circuit configuration, adjustment method, and two-amp current control means can be applied.

When the static charge on the photoreceptor is removed by light according to the present invention, a light bulb whose luminous intensity can be easily controlled is used, and in order to provide the optimum amount of irradiation light to both sides of the photoreceptor, the temperature of the light is detected, Correctly control the fluctuations in the lamp current of the electric light! This can be achieved by doing the following: It goes without saying that the present invention is similarly applicable to controlling the light amount of the exposure light source when a Loud fluorescent lamp is used as the original exposure lamp.

[Brief explanation of the drawing]

Figure 1 is a partial illustration of the configuration of a general copying machine, Figure 2 is the temperature and -relative light curve of the fluorescent lamp, Figure 3 is an illustration of the cold cathode lamp, and Figure 4 is the lamp current of the fluorescent lamp. - is a relative light curve. FIG. 5 is a rounded diagram explaining the method and apparatus of the present invention, and FIG. 6 is a functional explanatory diagram of an embodiment of the present invention. #! FIG. 7 is an example of a specific circuit of the light intensity control device portion in FIG. 6. 1O...Photosensitive member, 11...Photostatic eliminator, 12...Partial exposure device, 13...Pre-transfer exposure device, addition, father and ω・
...Lou electric light. 21...Fluorescent tube, M...Proximity conductor, δ and 6...
・Trans, group and 6...light intensity control device, group...
・Temperature detection means, 56B...2 Lamp current control means, 6
61 and 761...Thermistor, 662...Circuit section, 663 and 763...Photocoupler-0 Agent Yoshi Kuwahara Moxibustion ¥11 Closed Figure 2 1111111 Bow, 1F wall''M (Nakaugu 11p! 5
50 bu @61! ] 7th close

Claims (1)

[Claims] (11) In a copying machine using a photoconductive photoreceptor, a cold polar fluorescent lamp is used to remove static charge from the surface of the leading conductive photoreceptor, and the ambient temperature of the wrinkled polar fluorescent lamp is all processes of detecting;
111-j for controlling the cold cathode-fluorescent lamp 2 pump current by manually combining outputs corresponding to the detection outputs of the first and second folds; How to control the brightness of a light lamp. (2) In a copying machine using a leading conductive photoreceptor, a cold cathode fluorescent lamp is used to remove static charge from the surface of the leading conductive photoreceptor.
A temperature detecting means for detecting the ambient temperature of the ultra-low temperature fluorescent lamp and an output corresponding to the output of the temperature detecting means are manually operated.
A light intensity control device for a fluorescent lamp for a copying machine, which is connected to lamp current control means for controlling the lamp current of the cold Ik@fluorescent lamp. (3) When the cold cathode plate fluorescent lamp has a predetermined luminous intensity. 3. A light intensity control device for a fluorescent lamp for a copying machine according to claim 2, wherein said lamp current control means is adjustable so as to supply a lamp current corresponding to said light intensity. (4) A patent for lamp current control means that uses the output of the temperature detection means when the cold cathode wrinkled wall lamp has a predetermined luminous intensity as a reference output, and inputs the amount of displacement of the detection output from the chain reference output. A light intensity control device for a fluorescent lamp for a copying machine according to claim 2 or 3.