JPS61261753A - Copying machine - Google Patents

Abstract

PURPOSE:To prevent an original from the rise of temperature and discoloration and a user from accident such as a burn and to expand the life of an exposing lamp by executing proper control in accordance with the temperature of an original glass. CONSTITUTION:The copying machine is provided with a temperature detecting element arranged near the original glass to detect the temperature of the original glass, a mode discriminating means for comparing the output of the temperature detecting element with a prescribed temperature level and discriminating the copying mode, an exposing means for exposing an original set up on the original glass, a cooling fan for cooling the inside of the copying machine, and a temperature rise preventing means for controlling the exposing time of the exposing means, the copying interval of a copying means and the operation of the cooling fan in accordance with a mode set up by the mode discriminating means. If the temperature of the original glass detected by the temperature detecting element is increased, the exposing time of the exposing means is changed (intermittent exposure or stop of exposure). Thereby, the copying interval is also extended and the cooling fan may be stopped if necessary.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to electrophotographic reproduction.

(Prior art and problems to be solved by the invention) In an electrophotographic copying machine, an original placed on an original glass is irradiated with a high-intensity exposure lamp, and a photoreceptor is charged and exposed to light reflected from the original. Thereafter, each copy is made by transferring the toner image.

The temperature of the original glass increases by irradiation with the IAT lamp. In particular, when copying is performed continuously with a high-speed machine, etc., the temperature may become excessive due to radiation and convection caused by the heat generated by the exposure lamp, resulting in discoloration of the original, burns to the user, and shortening of the life of the exposure lamp. occurs.

Conventionally, therefore, one or more cooling fans such as line blowers are provided inside the machine, or the scanning distance is lengthened. If the temperature rises despite these two conditions, it is necessary to take measures such as lengthening the time interval between copies, turning off the exposure lamp, or pausing copying.

For example, in Japanese Patent Application Laid-open No. 54-32324,
By controlling the copy interval, it is possible to prevent the temperature of the document glass from rising. However, this method only operates a predetermined timer depending on the size and number of documents, and does not appropriately respond to temperature 'A'. In addition, installation of a cooling fan increases the cost by 1, increases the size of the copying machine, and causes noise problems.

Furthermore, in Japanese Patent Application Laid-Open No. 54-91332, the temperature is detected by a temperature detection element provided near the original glass,
The air volume of the cooling fan is controlled accordingly. However, with this method, trouble will occur if temperature rise cannot be prevented even when the cooling 77 units are operated at maximum. Furthermore, in order to prevent temperature rise, the higher the exposure lamp rating, the more a cooling fan with a higher air volume is required. As a result,
For example, in a halogen lamp, a blackening phenomenon occurs due to a decrease in lamp surface temperature, resulting in a shortened lamp life.

SUMMARY OF THE INVENTION An object of the present invention is to relate to a copying machine that can more efficiently prevent temperature rise of document glass.

(Means for Solving the Problems) The copying machine according to the present invention includes a temperature detection element that is provided near the original glass and that detects the temperature of the original glass, and a temperature detection element that compares the output of the temperature detection element with a predetermined temperature level. A mode determining means for determining the copying mode, an exposing means for exposing the original placed on the original glass, a copying means for copying the original, a cooling fan for cooling the inside of the copying machine, and a mode determining means. The exposure time of the exposure means corresponds to the set mode,
The present invention is characterized by comprising temperature rise prevention means for controlling the copying interval of the copying means and the operation of the cooling fan.

(Function) In order to prevent the temperature of the original glass from rising, it is effective to make the exposure time of the exposure means variable. Therefore, when the temperature of the document glass detected by the temperature detection element increases,
Change the exposure time of the exposure means (for example, intermittent or stop exposure). Along with this, the interval between copies will also be lengthened. In addition, the cooling fan is deactivated when unnecessary.

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

(a) System configuration The system configuration of this embodiment is schematically shown as 1 in FIG.

□ 1 CPU that controls this system
1 is connected to various inputs and outputs. Original glass 2
There is a temperature detection element (S1-5x9ttt) 3'6t in a part that does not contribute to image formation or in its vicinity.

3e4th7+. Koyu□□) '31
1.6 vs. 7′″′. 1″ temperature i″′μ°1]
The sensor is installed at a position where the temperature of the document glass itself 1 1 can be stably detected. Original: The large temperature signal generation circuit 4 outputs the output of the temperature detection element 3, +
:16°″r'+l°'m@y>i@lJv<'by>
dp° phase (temperature level to be input to CPU1) (P
E) Output. (Please note that A/
It is also possible to determine the temperature value on a program using a CPU with a built-in D converter. )Furthermore, keystrokes on the operating section 5 are input to the input port (PC). In addition, the input capo (PD) is controlled. For. Various, ) 8
Itch 6. ) input is connected”・5.

+lco・,l1, (output boat (PAo, 1.2...) is connected to the copying machine's exposure lamp 8, cooling fan 9, scanner motor 10, etc. via the driver 7.7... Drive the load.

Further, output capo) (P'B) drives various operation section displays 11.

Note that, as is well known, the CPU 1 includes a clock circuit 12.
and a reset circuit 13 are connected thereto.

(b) Original glass temperature and copy mode In this embodiment, the temperature T detected by the temperature detection element 3 is compared with two temperature levels T21T1 (here, T2>TI), and correspondingly, Copying is performed by automatically switching to one of three copy modes. Note that To(T, >
T, ) is the temperature level relevant to the operation of the cooling fan.

Each mode will be explained next. (Mode setting based on the original glass temperature will be explained in section (e).) First mode (T<T,): In continuous copying, the exposure lamp is always on.

Second mode (T, ≦T<T2): Even in continuous copying, the exposure lamp 8 is turned off when the optical system returns, and is turned on after the return is completed. This reduces the degree of increase in temperature of the original glass.

After lighting, when the light intensity of the exposure lamp 8 rises sufficiently, scanning is started. Therefore, the interval between copies becomes longer and the number of copies per unit time decreases.

3rd mode (T2≦T): After the copying process is completed, stop the copying process, enter cooling mode, and wait for a while on the operation panel.''
display. When the document glass temperature T falls below T1, copying in the second mode is restarted before the stop for cooling.

Examples of mode control are shown in FIGS. 2 and 3. Figure 2 shows
This is an example in which continuous copying starts at time [1] and ends at time L2. Since the original glass temperature T did not exceed T1, the copy mode is the first mode. During continuous copying, the exposure lamp 8 remains lit. this is,
This is because in high-speed machines, when the lamp is turned off during return, it takes time for the lamp light intensity to rise to a constant value at the time of the next copy, so the time per copy per meter decreases.

The cooling fan 9 operates at the start of copying ([1), and continues operating even after copying ends (t2) until the document glass temperature falls below To (t3). Of course, T at the end of copying.

If it is below, it will stop immediately. Note that the air volume of the cooling fan 9 is such that low-temperature blackening of the exposure lamp 8 does not occur.

FIG. 3 shows an example in which the document glass temperature T exceeds T1. Copying starts in the first mode at time t, ('r'<To). At time t5, T exceeds T, and the second
mode, the exposure lamp is lit intermittently, and the temperature is
The speed of 1 rise becomes slower. At time t6, T exceeds T2,
In the third mode, the copy operation is stopped and the exposure lamp is turned off. When T decreases and becomes lower than T, I, and J at time 17, copying is restarted in the first mode. Thereafter, the copy operation is performed while automatically switching the copy mode in the same manner.

Note that FIG. 4 is a timing chart of exposure lamp extinguishing control in the second mode. When the optical system finishes scanning (exposure is complete), the exposure lamp is turned off and the return operation begins. The next copy scan is started when the exposure lamp is turned on again after the return and the light amount reaches a predetermined value after a time L (usually several hundred milliseconds). Be sure to feed the paper by this time. Next, scan the copy and operate the registration rollers. Here, the exposure lamp lighting time for the next copy is set after the end of the return, but this is just an example, and the copy interval may be set separately on the program.

(c) Copying 70-- FIG. 5 shows the flow of the source program stored in the CPU 1 in this embodiment. CPU at power on
After resetting CPtJl, first, initial setting of CPtJl is performed (step Pi).

Next, inputs from the key operation unit 5 and control switch 6 are processed and output boat data is set (step P2).
. Next, key manual input and display data (number of sheets, etc.) are processed and determined (step P3). Next, a determination and determination of the handle operation mode is performed (step P4). Next, depending on the operating conditions, sequence control of the copy operation is performed (Step I), as will be explained in detail later. Finally, change the Drafuru Jam etc. at that time (Step 7 P6),
Return to step P2.

The copy process processing (step P5) is performed according to flowchart 1 shown in FIG. First, control the power supply of the main relay, etc., and adjust the temperature of the heat roller (
step P 1 fl ). Next, drive control of the main motor and the like is performed (stencil 11). Next, process control around the drum (P/C) such as charging and erasing is performed (step P12). Next, control the copy paper feed (
Step P13). Then, as explained in more detail later,
Optical systems such as a scanner and an exposure lamp are controlled (step P14). Finally, as will be described in detail later, the cooling fan is controlled (step P15), and the process returns.

(d) Optical system control Optical system control (step P14) is performed as shown in FIGS.
- This is carried out according to the flowchart in (). Note that the temperature control mode of the original glass 2 is determined by the 7-lug 1 and the 7-lug 2, as will be explained later in the section (e). First, as shown in FIG. 7(A), it is determined what the state number (() to 6) of the optical system is (step P20).
, “branch” according to its state number.

When the state number is 0, as shown in FIG. 7(B), the process immediately returns (standby mode).

When the state number is 1, as shown in FIG. 7(C), first, it is determined whether or not to start exposure (step P30). If not, return immediately. When the exposure start conditions are set by the drum process (step P12), the state number is 1, so next, turn on the exposure lamp (step P31), increment the state number by 1 (step P32), and return. .

When the state number is 2, as shown in FIG. 7(D), the first step is to determine whether the exposure lamp has finished starting up or not.
That is, 51 when the amount of light has reached a predetermined value.
It is determined whether or not (step P40). If not, return immediately. If completed, then ′□
It is determined whether the copy paper (・te,・puP13) is placed at a predetermined position (step P4).
1). If not, return immediately. If the paper has been fed, scanning is started (step P42), the state number is incremented by one (step P43), and the process returns.

When the state number is 3, as shown in FIG. 7(E), first, it is determined whether or not the registration switch is on (step P50). If not, return immediately. If it is on, the timing roller is driven (step P51), the state number is incremented by one (step P52), and the process returns.

When the state number is 4, as shown in FIG. 7(F), it is first determined whether the scan has been completed or not (
Step P60). If not, return immediately.

When finished, next, as explained in detail later,
Check the document glass temperature (step P61). Next, whether or not the document temperature glass T is less than or equal to T1 (that is, whether either 7 lag 1 or 7 lag 2 is not 0)
is determined (step P62), and if not (first mode), the exposure lamp is turned off (step P63). Then, the scan is started to return (step P64), and the state number is incremented by one (step P65).

When the state number is 5, as shown in FIG. 7(G), it is first determined whether the home position switch is on], that is, whether the scanner has returned to the home position ( Step P70). If not, return immediately. If it has returned, the return of the scanner is completed (step P71). Next, it is determined whether there is a next copy (step P72). If not, turn off the exposure lamp (step P79) and set the state number to 0.
and returns (step P80). If there is a next copy, then it is determined whether flag 2 is 1 (step P75). If flag 2 is not 1 but flag 1 is 1 (third mode), the timer is set to 11 (step P76), the state number is incremented by 1 (step P77), and the process returns. If the flag is a 1-power bow and there is no 1 j (first mode), the state number is set to 2.1 (step P78) and the process returns.

If the state number is 6, first, it is determined whether the timer has counted 11 (step P80). If not, return immediately; if [, has elapsed, set the state number to 1, step P81), and return.

(e) Mode setting based on document glass temperature The document glass temperature check (step P61) is performed according to chart 70 in FIG. First, it is determined whether the document glass temperature T is lower than the temperature level T1 (step P90).
. When it is low, that is, in the first mode, both 7lag 1 and 7lag 2 are reset (step P
91).

If not, then the document glass temperature T is at the temperature level T2.
It is determined whether or not it is lower (step P92). When it is low, i.e. in the second mode, 7 lag 1
and reset 7lag 2 (step P93
). If not, that is, if it is the third mode, 7 lag 2 is set (step P94).

7 Lag 1 and Flag 2 are used to control the copy interval and exposure lamp in optical system control (see section (d)).

(") Cooling Fan Control Cooling fan control (step r' 15 ) is performed according to chart 70 in FIG. 9. First, it is determined whether copying is in progress (step P 1 (10)).

If copying is in progress, turn on the cooling fan in step P1.
01), return. If not, the document glass temperature T or temperature level T. It is determined whether it is lower or not (
Step P102). If it is low, the cooling fan is stopped (step P103) and the process returns. If no,
Step P 1 (Proceeds to 11 and operates the cooling fan. In the following flow, the cooling fan is operated during copying or when T≧To.

(Effects of the Invention) According to the present invention, an increase in the temperature of the original can be prevented by performing appropriate control according to the temperature of the original glass. This also saves the life of the exposure lamp by preventing discoloration of the document and injury to the user (burns) 3. Temperature detection element.

I can do something.

[Brief explanation of the drawing]

Figure $1 is a conceptual diagram of a system according to an embodiment of the present invention. FIGS. 2 and 3 are graphs showing the relationship between document glass temperature and copying, respectively. FIG. 4 is a timing chart of exposure lamp blinking in the second mode. Figure 15 +1. It is a flowchart of the main flow of I-photographing. FIG. 6 is a flowchart of copy process processing. Figure 7 (A), (B), (C), (D), (E), (F
). (G) and (H) are 70-charts for optical system control. FIG. 8 is a 70-chart for checking the document glass temperature. FIG. 9 is a 70-chart of cooling fan control. 1...CPU, 2...Manuscript glass, Patent applicant Minolta Camera Co., Ltd. Agent Patent attorney I mentioned above 2 idiots No. 5ffl JP-A-61-261753 (7) Written amendment to the procedure on page 6 (spontaneous) ] 1986 IJ] 29th To the Commissioner of the Patent Office, 1 Display of the case 1985 Patent Application No. 105463 2 Name of the invention Copy machine 3 Person making the amendment Relationship to the case Patent applicant name (607) Minolta Camera Co., Ltd.
Shima Hideoyo 2. ':M
III Hidetoshi Shima A: I4 agent 5th supplement'if2. ## With σZ (Voluntary amendment) 6 Column for detailed explanation of the invention in Showa 1 book subject to amendment. drawing. 7. Contents of amendment A. The following points in the description will be corrected. Detailed Description of the Invention Column (1) 11th line 6th line "iα chini" [First, as will be explained in detail later, check the temperature of the original glass (template) 25) . Next, the temperature is
Sharpening higher than F2 (third mode), i.e. flag 2
If the state number is not 0 (step P26), the state number is incremented by 1 (Stember r'27) and corrected to l. (2) Page 13, line 15 [It says 751, correct it to 731.] (3) Page 13, line 16, ``If it is 1 (3rd mode) - 1, correct it to 4 if it is 1 (2nd mode). (4) Page 13, line 20 Return after 1. If the flag is 2 or '1 (third mode), set the state number to 0 (step I'' 74.) and return. ”. B3 drawing Figure 7 (A), (B), (C), (r)), (
E), (F). (G), (1-() are corrected as shown in the attached sheet.

Claims (1)

[Claims] (1) A temperature detection element provided near the original glass for detecting the temperature of the original glass; a mode determination means for comparing the output of the temperature detection element with a predetermined temperature level to determine the copying mode; an exposure means for exposing an original placed on the original; a copying means for copying the original; a cooling fan for cooling the inside of the copying machine; 1. A copying machine comprising a temperature rise prevention means for controlling the copying interval and the operation of a cooling fan.