JPS61200567A - Flash fixing device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is a fixing device of a recording device such as an electrophotographic copying machine or a facsimile receiver, and in particular, fixes unfixed 9I formed on a recording material by a developer by discharging it. The present invention relates to a flash fixing device that performs fixing using energy from a tube, and a recording device having this flash fixing device.

(Prior Art) This fusing bag # is advantageous compared to other fusing methods, such as heated roller fusing, because it has no waiting time, low power consumption, and no risk of overheating. In addition, compared to pressure fixing, it has advantages in that it is lighter in weight, has fewer drive irregularities, does not depend on the quality and thickness of pine wood paper, and does not have the transfer paper expand or contract. Used in electrophotographic copying machines, etc.

Conventional flash fixing devices use xenon lamps (hereinafter referred to as
A discharge tube such as a Xe Lang) is placed facing the recording material on which an unfixed image has been formed by the developer, and the discharge tube is discharged, and the flash energy melts the developer on the recording material and fixes it. It looks like this. The energy supplied to the unfixed image by one light emission of the discharge tube is determined by the light emission time of the discharge tube. -The energy required to fix an unfixed image, that is, the amount of energy required to melt the developer, varies depending on the density of the developer in the unfixed image, and when the density is low and the amount of developer is small, the amount of energy may be small. However, if the concentration is small, a large amount of energy is required. Therefore, in the past, the light emitting time of each discharge tube was determined so that a substance with a clear density could be fixed.

(Problem to be Solved by the Invention) However, in the case of such a conventional example, when the amount of developer that forms an unfixed image such as one with low density is small, for example, when the image to be fixed is one character, However, a constant high level of energy is supplied and energy is wasted. Further, there is a problem in that the supplied energy is excessive and the developer rapidly melts and scatters. Furthermore, since high energy is constantly generated, there is a problem in that the life of the discharge tube is shortened as a result.

The present invention has been made to solve the problems of the prior art, and its purpose is to increase the density corresponding to the unfixed image (directly or from the latent image potential on the photoreceptor or from the original). To provide a flash fixing device that eliminates wasted energy and extends the life of the discharge tube by adjusting the supply energy supplied from the discharge tube in accordance with the density obtained by density detection etc. be.

J, or "F Remaining Colors (Means for Solving the Problem) In order to achieve the above object, the present invention provides a density detection means for detecting the density corresponding to an unfixed image, and a method using the density detection means. The apparatus is equipped with an energy control means for controlling the discharge energy supplied per unit area on the recording material by the discharge tube with respect to the detected concentration.

(Example) The present invention will be explained below based on the illustrated example. In FIG. 1 showing an electrophotographic copying machine using a flash fixing device according to an embodiment of the present invention, reference numeral 1 denotes a document mounting table made of a transparent member, which moves back and forth in the direction of the arrow. Reference numeral 2 denotes a light-condensing light transmitting body that slits the light image of the original image on the original platen 1 onto the photosensitive drum 3, and the photosensitive drum 3 rotates in the direction of the arrow. A corona charger 4 charges the photosensitive drum 3 uniformly. 5 is a developing device;
An electrostatic latent image formed by sawing a light image onto a uniformly charged photosensitive drum 3 using a condensing light transmitting member 2 is visualized. On the other hand, a transfer paper P serving as a recording material is fed onto the drum surface by a paper feed roller 6 and a reso roller 7, and a surface image on the photosensitive drum 3 is transferred by a transfer charger 8. Thereafter, the transfer paper is separated from the photosensitive drum 3 by the separating means 9, and the guide 1
Sent to 0. A fixing cartridge 11 in the form of a cartridge is disposed above the guide 10 as a flash fixing device, and flash light is irradiated onto the transfer paper conveyed on the guide 10 to melt and fix the toner on the transfer paper. It has become. Further, the transfer sheet is sent to the paper ejection belt unit 12 and ejected onto the tray 13. Further, the toner remaining on the photosensitive drum 3 is scraped off by the cleaning means 14 and collected.

The fixing car) IJ fluoride will be explained in detail below. As shown in FIG. 3, there are a fixing cartridge 1lij and three fixing device main bodies 17a each having a discharge tube that emits flash light inside the housing 15.
, 17b, and 17c are incorporated. In this embodiment, the fixing device main body incorporated in the housing 15 includes a first fixing device main body 17a, a first fixing device main body 17a,
The second fixing device fIL main body 17c and the third fixing device main body 17c are arranged in this order, and as described later, the transfer paper is divided in the width direction and the areas corresponding to each fixing device are fixed. It is supposed to be done. Furthermore, each fixing device main body 17
a, 17b, and 17c are arranged with their positions shifted with respect to the direction of movement of the transfer paper P.

Taking the first fixing device main body 17a as an example, each fixing device main body includes a xenon lamp (hereinafter referred to as Xe lamp) 16a as a discharge tube and a
Reflective shade 18a that reflects the light emitted from the lamp 16a
and a glass 19a that protects the Xe lamp 16ai. That is, the Xe lamp 16a is attached to the reflective shade 18a having a parabolic cross-sectional shape, and the reflective shade 1
The opening of 8a is closed with glass 19a. The second and third fixing device main bodies 17b and 17c are also
It has the same configuration as the fixing device main body 17a.

The fixing cartridge 11 is removably attached to the copying machine main body as shown in FIG. A fixing cartridge (fixing cartridge) ridge 11 is guided and supported along the fixing cartridge and can be attached to and removed from the main body of the copying machine, and a handle portion 15a is formed on the front side of the fixing cartridge 11.

At the rear end of the fixing cartridge 11, Xe lamps 16a and 16b are provided for a lamp drive circuit as a discharge energy supply means provided on the copying machine main body side.

A coupling terminal 21 for electrical connection is provided. From the coupling terminal 21, each fixing device main body 17
A cord 254'- is connected to the terminal 22' of each of the Xe lamps a, 17b, and 17c.

On the other hand, on the side wall 24 on the copying machine main body side, as shown in FIG. A connector 27 on the main body side is attached to connect the fixing cartridge 11, etc., and when the fixing cartridge 11 is inserted, it is guided by the guide rail 20 and the fixing cartridge 1
One coupling terminal 21 is connected to a main body side connector 27, and each Xe lamp 16a, 16b, 16c is electrically connected to a lamp drive circuit.

Further, a cleaner 28 is provided at right angles to the guide rail 20 on the cartridge 15 front side of the guide rule 20.

In FIG. 2, each Xe lamp 16a, 16b,
16c schematically shows drive control. In the figure 2
A drive circuit for driving a 9-digit Xe rung is shown. 30
is a density detection means for detecting the image density of an unfixed image;
The density of each image fixed by the e-lamps 16a, 16b, and 16c is detected. The image density may be determined by detecting the density of the toner image transferred onto the transfer paper, the density of the document, or the toner density on the photoreceptor 3. As the concentration detection means 30, an optical sensor such as CdS or C0D (a charge coupling device) is used. Reference numeral 31 in the figure is a control means for controlling the light emission time of each Xe lamp 16a, 16b, 16c in response to the concentration signal detected by the concentration detection means 30, and is connected to the drive circuit 29 described above. Reference numeral 32 in the figure is a calculation section that calculates the signal detected by the concentration detection means 30 into an input signal to the control means 31.

Control of driving each of the Xe lamps 16a, 16b, and 16c will be explained below with reference to FIGS. 6 to 8.

Figure 6 shows the drive circuit of the Xe lamp, and R1
-R11 is a resistance, C! ~C2o is a capacitor, Dl~D
6 is a diode, Ll is a coil, 5CRI to 5CRe
is a thyristor, Tz ~ Ta i), Xe,
~Xe3 is a Xe lamp, DR8~DR6 driver,
PD has 7 sensors, 8l-8ll has input 5W1cPU
It is a microcomputer. FIG. 7 is a flowchart showing control.

First, connect S (not shown) to the AC 100V line shown in Figure 6.
Power is supplied by W, and low voltage power is supplied to the CPU, etc. to an AC-DC converter (not shown), and at the same time, the supplied AC 100V is boosted to QDC 280V by resistor R1, capacitor C1, and diodes D, ~D3. Voltage doubler, main capacitor C! To Xe Lang Xe,
~Xe3 is fully charged in order to emit light with a predetermined energy. The voltage charged in the main capacitor C2 is divided by resistors R2 and R3 and input to the A/p input terminal of the CPU for constant monitoring.

At this time, in the flowchart shown in FIG. 7, when the main SW is turned on, the CPU starts 5 tart L, and in step 1, the memory, Ilo, etc., undergoes all initialization to set all predetermined conditions, and in step 2, the CPU starts charging KL. Starting with monitoring the voltage, checking various conditions such as the presence or absence of transfer paper and the number of copies to be made, and reading these conditions and proceeding to step 3 only when the state is ready for copying. In step 3, a copy start switch (not shown) is checked, and if it is not pressed, the process returns to step 2 and this is repeated; if it is pressed, the process proceeds to step 4. Step 4 is to control the timing of various processes, and if you want to go further, first count the timing pulses obtained from the main motor etc. with a counter, etc., and turn on the exposure lamp, document platen forward and backward equal volume loads.
, the OFF timing is set in advance in a resistor, etc., and the counter and these registers are compared, for example, every time the count increases, and the corresponding load is turned ON.

This is to turn off the power. In step 5, whether or not the machine is operating normally is monitored using input means (not shown) provided at various locations, and based on these conditions, necessary data is stored, rewritten, etc. At step 6, which is also carried out to handle abnormalities at certain times, the fixing timing input means $1, which is an input to the CPU shown in FIG. 6, is checked.
If it is not the fixing timing, proceed to step 7. In step 7, it is determined whether or not the process is finished. If the process is not finished, the process returns to step 4 and this is repeated. If the process is finished, the process returns to step 2. become a state. If the fixing timing is received from the fixing timing input means 81 in step 6, the process proceeds to step 8. From this point on, the following various conditions obtained in step 2 or step 5,
In step 8, the image density is read from the photosensor shown in Fig. 6, A/Dφ is input and A/D converted, and the charging voltage is input to A/Dφ and A/P converted in the same way. , calculate the appropriate light emission time from the cartridge signal input to the IPI of the CPU (in the present invention, ON = black, 0FF = colored cartridge), store this value in the register, and in step 9, CPU I
An appropriate number of times of light emission is selected based on the length of the transfer paper P in the feeding direction inputted to F5 and stored in a register, and in step lO, the length of the transfer paper P in the main scanning direction inputted to IP3 to IP5 of the CPU is Assuming that an appropriate number of arc tubes (for example, Xe lamps can fix about 70 directions,
In the present invention, since there are three series, 210sa++
can be fixed in the main scanning direction, and therefore the number of arc tubes in the main scanning direction can be controlled at intervals of 70+w). As mentioned above, the values stored in these registers are used in step 4. To explain the operation in more detail, at the fixing timing, the trigger signal of the Xe lamp lXe1 is input from OPφ as shown in FIG. The first shot is output, and this ρ signal is the thyristor 8CR1゜5.
This signal is sent to the gate of CR2 via driver DRI.

5CR2 turns ON, and thyristor 5CRI turns on transformer Ts.
A high voltage is applied to the trigger electrode of the Xe rung Xel through the Xe rung. At this time, the Xe lamp Xel starts emitting light and emits light. At the same time, since the thyristor 5CR2 is also turned on, a discharge current flows and a complete light emitting state is achieved. Next, when the above-mentioned light emission time VC is reached (Ts shown in FIG.
a) The CPU is sent to the gate of the thyristor 5CR3 via the OPI 7 signal St-driver DR2'. At this point, thyristor 5CR3 is turned on,
As a result, the electric charge in the capacitor C6 that had been charged through the υ resistor R8 is discharged through the thyristor 5CR3', so that the thyristor 5CR2 is turned off without applying a reverse bias to the thyristor 5CR2, which had been turned on. Therefore, the Xe lamp Xel stops emitting light. Also, after Tm (charging time) from the ON of thyristor 5CR3,
Conditions (length in main scanning direction), Xe lamp Xe 1
→Xe lamp Xe2-*Xe lamp Xe3. Xe lamp Xe1-+Xe lamp Xe2, or Xe lamp X
el is repeated a predetermined number of times.

FIG. 8 shows a timing chart of light emission of each Xe rung, and T1a, Tl-b, Tl-c
is each Xe rung lighting time, Tt is main capacitor C1
Shows the charging time.

Next, the operation of the fixing device of this embodiment will be explained. First, the transfer paper P on which an unfixed toner image has been formed on the upper surface in the transfer process is conveyed onto the guide 9. The density of the unfixed image of the toner on the transfer paper in the area to be fixed is detected by each density detection means 30, and each Xe lamp 16a is detected in accordance with the detection signal.

The light emitting times 16b and 16c are set to appropriate values that allow all the toner in each fixing area to be completely melted.

That is, the energy supplied to the toner is adjusted by lengthening the emission time when the density is high and shortening it when the density is low. Figure 11 shows the light emission characteristics of the Xe lamp. For example, if the light emission time is T1 to T, r, then
The luminous energy supplied to the fixing area increases accordingly.

Assuming that the maximum width of the transfer paper is used, as shown in FIG. The area AI in the figure is fixed by emitting light.Next, while the transfer paper P moves to the position of the second Xe lamp 16b, the main capacitor C2 is charged to a predetermined value (ISi'
1 becomes T2), the second Xe rung 16b emits light for a predetermined time (Tt-b) corresponding to the concentration of that part, and becomes B in the figure.
1 area is fixed. Next, while the transfer paper P moves to the position of the third Xe lamp 16c, the main capacitor C
2 is charged to a predetermined value (charging time is 'r2), and the third Xe lamp 16a emits light for a predetermined time (Ttc) corresponding to the density of that portion, thereby fixing the area C1 in the figure.

In this way, each Xe lamp 16a, 16b is divided into time periods.
, 16c repeatedly emit light in order, and the following types are Ax l B
2 + C2e Aa .

Here, the timing of the light emission is set so that there is at least no gap between adjacent fixing areas in the direction of travel of the transfer paper, for example, area A1 and area A2, and The Xe lamps 16a are arranged so that there are no gaps between adjacent fixing areas in the perpendicular direction, for example, A1 and B1 and B1 and C1.

The arrangement of 16b and 16c is considered.

Fig. 10 shows the effective l,
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Thread, /-L2,ru. 7 ;-1kfAmuqz X1
7, y 7'n It='8Jn, if false butterfly transmission, number, tl 1-cho-no-seed @ +< y=, ヮ了717゛1ゝゝゝ.

Since the light emitting time of the Xe lamp is changed in accordance with the density of each image, the light emitting energy of the Xe lamp is efficiently used, eliminating waste.

Here, using the apparatus of this embodiment, Xe due to the density difference of the original is
The results of a comparison test of lamp life are shown. A4 size copy paper was used, and continuous copies were made of a black solid original and a line image (the area of the line image occupies 6% of the copy paper). As a result, 2,000 sheets of black solid paper, and 36 sheets of line image originals.
It became 00 pieces. In the case of a conventional Xe lamp, the light emitting time is set so as to fix a solid black image, and the fixing performance can be improved compared to the case of a conventional single lamp.

In the above embodiments, the discharge energy is controlled by changing the light emission time, but the number of light emission times of the Xe lamp may also be controlled.

In other words, the Xe lamps are used to emit light for a fixed period of time and irradiate the same area with emitted light energy, thereby increasing the energy supplied per unit area of the transfer paper and improving the fixing performance. Therefore, the energy supplied in one light emission is small, and the light emission interval is shortened.

In this embodiment, only the fixing device main body 17 is incorporated as the fixing cartridge 11, but the first
As shown in FIGS. 2 and 13, the photosensitive drum 3, the corona charger 4, the developing device, and the cleaning means 14 may be integrated into the main body of the fixing device and the mulberry.

The present invention can also be applied to a flash fixing device that is not a cartridge, that is, a discharge tube is installed in the main body of the copying machine and is directly attached to the next terminal. Furthermore, it can also be applied to a type in which the fixation is performed using a single discharge tube instead of a plurality of discharge tubes.

The above description has been about a flash fixing device applied to an electrophotographic copying machine, but it is not limited to electrophotographic copying machines, and is also used in other devices such as facsimile receivers and laser beam printers, which fuse and fix unfixed images with developer. The present invention can be applied to various apparatuses having a fixing process.

(Effects of the Invention) The present invention has the structure and operation described above, and instead of constantly supplying a constant high energy from the discharge tube to fix unfixed images with high density as in the past, Since only the amount of energy necessary to melt the developer that forms the unfixed image is supplied to the discharge tube according to the density of the image, there is no loss of energy as in the conventional method, and the discharge The life of the tube can be extended. In addition, there is no need to supply excessive energy to low-density unfixed images as in the past, so there is no developer scattering, and good fixing performance can always be obtained. is obtained 0

[Brief explanation of the drawing]

! @Figure 1 is a control block diagram for controlling the drive of the discharge tube of a flash fixing device according to an embodiment of the present invention, and the second cause is a control block diagram of an electrophotographic copying machine using a flash fixing device according to an embodiment of the present invention. Schematic configuration diagram, Figure 3 shows 7 of the device in Figure 1.
A perspective view showing a part of the lash fixing device broken away, No. 4
The figure is a schematic side view of the flash fixing device shown in FIG. 3, FIG. 5 (a) is a perspective view showing the flash fixing device and guide rail of the device shown in FIG. A side sectional view showing the vicinity of the connector on the main body side at the far end of the guide rail of the device shown in the figure, FIG. 6 is a control circuit diagram of the 7-lash fixing device of the device shown in FIG. 1, and FIG. 7 is a control circuit diagram of the flash fixing device of the device shown in FIG. Flowchart, FIG. 8 is a timing chart of the control circuit diagram of FIG. 6, FIG. 9 is a diagram showing the fixing area on the recording material fixed by the flash fixing device of FIG. 2, and FIG.
The figure is a schematic side view of the vicinity of the discharge tube showing the fixing area fixed by one of the discharge tubes of the seven-lash fixing device of the present invention, and FIG. 11 is the relationship between the amount of light emitted by the discharge tube and the light emission time of the device of FIG. 10. FIG. 12 is a perspective view showing a state in which the sound of the flash fixing device of an electrophotographic copying machine using all the flash fixing devices according to another embodiment of the present invention is extracted; FIG.
This figure is a perspective view of the seven-lash fixing device shown in FIG. 12. Explanation of symbols 11... Flash fixing device 15... Cartridges 16a, 16b, 16c = Xe lamp (emission jk! 1. tube) 17a, 17b, 17cm Fixing device main body 18a, 13
b, 18cm reflective shade' 19a, 19b, 19c = Glass 20...Guide rail 21...Coupling terminal 27.
... Main body side connector 30 ... Concentration detection means Fig. 10 Tt Tl'' Ginma

Claims (3)

[Claims] (1) In a flash fixing device that melts and fixes an unfixed image formed by a developer on a recording material by discharge energy from a discharge tube, a density detection means detects the density corresponding to the unfixed image. and an energy control means for controlling discharge energy supplied per unit area on the recording material by the discharge tube with respect to the density detected by the density detection means. . (2) The flash fixing device according to claim 1, wherein the energy control means controls the discharge time of the discharge tube. (3) The flash fixing device according to claim 1, wherein the energy control means controls the number of discharges of the discharge tube.