JPH01267630A - Copying lamp controller for copying machine - Google Patents

Abstract

PURPOSE:To prolong the service life of a copying lamp by controlling the duration of application of a maximum voltage to the copying lamp at the time of actuating the copying lamp so as to be longer in response to the time elapsed since the copying lamp was turned off previous time. CONSTITUTION:In a 1st copying cycle I, the period Ta when the maximum voltage Vf is impressed is always set longer, and the light quantity of the copying lamp 7 surely reaches a rated light quantity Lr in a time T1 when the copying lamp 7 starts irradiating the leading edge of an original. In a copying cycle II for copying the 2nd and subsequent sheets, a period Ta' when the maximum voltage Vf is impressed on the copying lamp 7 is set shorter so that the light quantity of the copying lamp 7 at the end of that impression of the maximum voltage Vf slightly exceeds the rated light quantity Lr. Thus, the period Ta when the maximum voltage Vf is impressed on the copying lamp 7 is shortened to prolong the service life of the copying lamp 7.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control device for a copy lamp in a copying machine.

[Conventional technology]

Conventionally, when controlling the lighting of copy lamps when the same document is continuously copied onto multiple sheets of paper using a copying machine, as shown in (a) in FIG. When starting up the copy lamp in each copy cycle 1', ■', etc., such as the copy cycle 1' and the copy cycle ■' for copying the second copy, the maximum voltage is always applied to the copy lamp for a certain period of time Ta'. After applying Vf, the rated voltage ■r was applied to obtain the rated light amount Lr shown in FIG. 5(b).

[Problem to be solved by the invention]

However, if the application time Ta' of the maximum voltage f to the copy lamp at the start-up of the copy lamp is constant for each copy cycle, as described above, the first sheet in continuous copying In the copy cycle ■' for copying, the light intensity of the copy lamp is still at the rated light intensity L at time t, ' when the copy lamp starts illuminating the leading edge of the document.
r has not been reached, and there is a problem in that so-called fogging occurs at the leading edge of the copied image.

In addition, in the copy cycle ■' for copying the second and subsequent copies where the copy lamp has an afterglow from the previous copy, the light intensity of the copy lamp at the end of application of the maximum voltage Vf is the rated light intensity Lr. Therefore, an excessive voltage is applied to the copy lamp at the time of start-up, which results in an unnecessary reduction in the life of the copy lamp. Note that t and l are the times at which the copy lamp starts irradiating the leading edge of the document in the copy cycle 2' for copying the second sheet.

[Means to solve the problem]

In order to solve the above-mentioned problems, the copy lamp control device for a copying machine according to the present invention has the aim of increasing the maximum voltage application time to the copy lamp when starting the copy lamp from the time when the copy lamp was previously turned off. It is characterized in that it is configured to be controlled so that the elapsed time becomes longer as the elapsed time becomes longer.

[For production]

According to the above configuration, the application time of the maximum voltage to the copy lamp at startup is controlled so that it becomes longer as the time elapses since the copy lamp was last turned off. If a long time has elapsed since the copy lamp was last turned off, such as when copying the first sheet in continuous copying, the maximum voltage is applied to the copy lamp for a sufficiently long time, and the copy lamp does not touch the leading edge of the document. It is possible to ensure that the light amount of the copy lamp reaches the rated light amount at the time when irradiation starts.

On the other hand, if the time elapsed since the last time the copy lamp was turned off is relatively short, such as when copying the second and subsequent sheets in continuous copying of multiple sheets, the maximum voltage application time to the copy lamp at startup is made relatively short, so that the amount of light from the copy lamp at the end of application of the maximum voltage is slightly higher than the rated light amount. This prevents excessive voltage from being applied to the copy lamp, thereby extending the life of the copy lamp.

〔Example〕

An embodiment of the present invention will be described below based on FIGS. 1 to 4.

As shown in FIG. 2, a copying machine equipped with a copy lamp control device according to the present invention has an automatic document feeder 2 in the upper part of a main body 1 of the copying machine. This automatic document feeder 2
, the originals 4, 4, . . . are set on the original tray part 3.
. . are sequentially supplied onto the transparent document table 5, and the copied documents 4, 4, . . . are sequentially discharged to the document discharge section 6.

Below the document table 5, there is a copy lamp 7, which is composed of a halogen lamp or the like, and which irradiates the document 4 that has been positioned at a predetermined position on the document table 5 by the automatic document feeder 2, and a lens 8 that directs the reflected light from the document 4. An optical system 14 is disposed that includes a plurality of mirrors 10 to 13 that guide the light to the photoreceptor 15 via the mirrors 10 to 13.

The photoreceptor 15 is supported under the optical system 14 so as to be freely rotatable in the clockwise direction in FIG. 16, it can be charged to a predetermined potential. When the surface of the photoreceptor 15 is charged to a predetermined potential, the photoreceptor 15 is exposed to reflected light from the original 4 via the optical system 14, thereby forming a corresponding image of the original 4 on the photoreceptor 15. An electrostatic latent image is formed.

The electrostatic latent image described above is developed with toner (not shown) supplied to the surface of the photoreceptor 15 from the developing device 17, and a toner image corresponding to the image of the document 4 is formed on the photoreceptor 15. Subsequently, the paper 23 is fed from the manual paper feed unit 18 or one of the paper feed trays 19, 20, or the paper feed unit 21 to the photoconductor 15 via the registration roller 22, and the toner image on the photoconductor 15 is transferred. The image is transferred onto the paper 23 by the charger 24. Subsequently, the paper 23 is peeled off from the photoreceptor 15 by the peeling charger 25. Note that the toner remaining on the photoreceptor 15 after the toner image is transferred to the paper 23 is collected by a cleaning device 26 and removed from the surface of the photoreceptor 15, and the electric charge remaining on the surface of the photoreceptor 15 is removed by a static elimination lamp. The static electricity is removed by a static eliminating means 27 such as the above.

The paper 23 peeled off from the photoconductor 15 is sent to the fixing section 30 by the conveyor belt 28, and after the toner image is fixed on the paper 23, it is transferred to the fixing section 30 via the switching gate 31 in the case of single-sided copying. It is discharged to the discharge tray 32. Further, in the case of double-sided copying or composite copying, the paper 23 that has passed through the fixing section 30 is guided to the conveyance path 33 by the switching gate 31, and in the case of composite copying, it is ejected as is to the intermediate tray 34, while in the case of double-sided copying, If so, the paper is turned over by a reversing mechanism 35 and then discharged onto the intermediate tray 34.

When a predetermined number of sheets 23, 23, . . . are accumulated on the intermediate tray 34, the sheets 23, 23, . . .
The sheets are sequentially sent out from the intermediate tray 34 starting from the topmost sheet and guided to the photoreceptor 15, where they are subsequently copied.

As shown in FIG. 3, this copying machine is equipped with a microcomputer 37 that also has the role of a copy lamp control device, and this microcomputer 37 controls each part of the copying machine main body 1 according to a control program stored in advance in a ROM 38. It is configured to control the Further, a RAM 40 connected to the microcomputer 37 is used as a buffer memory, a flag necessary for copy control, an area for other calculations, and the like.

The signal input device 41 is configured to input signals such as a detection signal from a key switch or a paper passage detection switch (not shown) provided in the copying machine main body 1 to the microcomputer 37 via an interface circuit 42. or,
Interface circuit 43 to microcomputer 37
The driver array 44 connected to the driver array 44 is configured to control a plurality of display circuits 45, 45, . There is.

Further, the microcomputer 37 is connected to a copy lamp regulator circuit 47, and the copy lamp regulator circuit 47 controls the voltage applied to the copy lamp 7 based on a signal from the microcomputer 37.

In the above configuration, when a plurality of sheets are continuously copied from the same document 4, in the present invention, as shown in FIG. 1, the elapsed time Tb from when the copy lamp 7 was turned off in the previous copy cycle becomes longer. Accordingly, the application time Ta of the maximum voltage Vf to the copy lamp 7 at the time of starting the copy lamp 7 in the current copy cycle is lengthened stepwise. Further, in the copy cycle I for copying the first sheet in continuous copying, since there is no afterglow phenomenon in the copy lamp 7, the longest time is always selected as the application time Ta of the maximum voltage Vf. In addition, each copy cycle ■・
(2) operates at a constant cycle T, and this cycle T is determined according to the size of the paper 23, the copying magnification, etc.

By doing as described above, even in the copy cycle f for copying the first sheet, at time t when the copy lamp 7 starts irradiating the leading edge of the original 4, the light amount of the copy lamp 7 will surely be the rated light amount Lr. seems to have reached . In addition, in the copy cycle (■) for copying the second and subsequent copies, the light intensity of the copy lamp 7 at the end of application of this maximum voltage (■r) is set as the application time Ta of the maximum voltage Vf to the copy lamp 7. A relatively short period of time that slightly exceeds the rated light 11Lr will be selected, so the copy lamp 7
By shortening the application time Ta of the maximum voltage Vf to the copy lamp 7, it is possible to extend the life of the copy lamp 7. Note that t2 is the time when the copy lamp 7 starts irradiating the leading edge of the original 4 in the copy cycle (3) for copying the second sheet.

Hereinafter, the control procedure by the microcomputer 37 during copying will be briefly explained with reference to the flowchart in FIG. However, here, the elapsed time Tb from when the copy lamp 7 was turned off in the previous copy cycle is calculated as the first to third comparison values X+% X2, X3 (however, X
, >x, >x, .), the application time of the maximum voltage vr to the copy lamp 7 in the current copy cycle is switched in four stages.

First, prior to copying, an end value Te is set to the elapsed time Tb from when the copy lamp 7 was turned off in the previous copy cycle (sl). When determining the length of elapsed time Tb from when the copy lamp 7 was turned off in the previous copy cycle (described later), if the end value Te is set to Tb, this end value Te is determined in the subsequent copy cycle. The value is set to such a large value that the maximum time is selected as the application time Ta of the maximum voltage Vf to the copy lamp 7.

When the end value Te is set to the elapsed time Tb, it is then determined whether the print switch is turned on or not. If it is not turned on, the process returns to Sl, and if it is turned on, the copying operation and Paper feeding is started (S3).

Next, it is determined whether the copy lamp 7 is turned on (S4), and if the copy lamp 7 is turned on, the maximum voltage Vf is immediately applied to the copy lamp 7 (S5).

Subsequently, the elapsed time Tb is the first comparison value x.

It is determined whether the elapsed time T is greater than (S6), and the elapsed time T
If b is larger than the first comparison value x, the longest time Ta1 is set as the application time Ta of the maximum voltage Vf to the copy lamp 7 in the current copy cycle (S7).

In S6, the elapsed time Tb is the first comparison value X.

If it is below, then it is determined whether the elapsed time Tb is greater than the second comparison value Xz (Xz < x,) (S8), and if the elapsed time Tb is greater than the second comparison value For example, the second longest time Ta2 is set as the application time Ta in the current copy cycle (S9).
).

In S8, if the elapsed time Tb is equal to or less than the second comparison value x2, then the elapsed time Tb is set to the third comparison value X3.
It is determined whether it is larger than (Xs < x2) (S10
), if the elapsed time Tb is greater than the third comparison value x3, the third longest time Ta3 is set as the application time Ta in the current copy cycle (Sll);
Further, in S10, if the elapsed time Tb is less than or equal to the third comparison value x3, the shortest time Ta4 is set as the application time Ta (S12). As a result, the elapsed time T since the copy lamp 7 was turned off in the previous copy cycle
Depending on the length of b, the application time Ta of the maximum voltage Vf to the copy lamp 7 in the current copy cycle is Ta
+”T a Set to any value of 4.

Next, the application time Ta of the maximum voltage Vf to the copy lamp 7 in the current copy cycle set in steps 86 to S12
It is determined whether or not the application time Ta has ended (S13), and if the application time Ta has ended, the rated voltage Vr is applied to the copy lamp 7.
is applied (314). Thereafter, it is determined whether or not the copy lamp 7 has been turned off after the irradiation of the original 4 (S
15) When the copy lamp 7 is turned off, counting of the elapsed time Tb since the copy lamp 7 was turned off is started in preparation for the next cohesion cycle (S16). Subsequently, it is determined whether or not the predetermined number of copies in continuous copying has been completed (517), and if the predetermined number of copies have not been completed, the process returns to S4 to start copying the remaining number of sheets, and the predetermined number of copies have been completed. If so, return to Sl and prepare for new copying.

〔Effect of the invention〕

As described above, in the copy lamp control device for a copying machine according to the present invention, the maximum voltage application time to the copy lamp at the time of starting the copy lamp is longer than the elapsed time since the copy lamp was last turned off. It is configured to be controlled so that it becomes longer as the length increases.

As a result, if a long time has elapsed since the copy lamp was last turned off, such as when copying the first sheet in continuous copying of multiple sheets, the maximum voltage is applied to the copy lamp for a sufficiently long time, and the copying It is possible to ensure that the light intensity of the copy lamp reaches the rated light intensity at the time when the lamp starts illuminating the leading edge of the document, and also to ensure that the light intensity of the copy lamp reaches the rated light intensity at the time when the lamp starts illuminating the leading edge of the original. If the elapsed time after being turned off is relatively short, the time for applying the maximum voltage to the copy lamp at startup will be relatively short, and the light intensity of the copy lamp at the end of application of the maximum voltage will be lower than the rated light intensity. By setting the voltage to a slightly higher level, application of excessive voltage to the copy lamp is prevented, and the life of the copy lamp can be extended.

[Brief explanation of the drawing]

1 to 4 show examples of the present invention, in which FIG. 1 is a time chart showing the relationship between the voltage applied to the copy lamp and the amount of light from the copy lamp, and FIG. An explanatory diagram showing the overall configuration of a copying machine equipped with a copy lamp system '4'B device, FIG. 3 is a block diagram showing the control system of the copying machine in FIG. 2, and FIG. 4 is a block diagram showing the control system of the copying machine in FIG. FIG. 5 is a flowchart showing the control procedure of the conventional copy lamp control device (copy lamp control device), which shows the relationship between the voltage applied to the copy lamp and the amount of light from the copy lamp.
School 1, Diagram 3〉〉〉〉− Nashi Anaguchi

Claims (1)

[Claims] 1. The control is configured such that the maximum voltage application time to the copy lamp when starting the copy lamp becomes longer as the time elapses since the copy lamp was last turned off. Features a copy lamp control device for a copying machine.