JP3242551B2 - Lighting equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illumination device for illuminating a document used in an electrostatic copying machine or the like. In particular, the present invention relates to a lighting device of a copying machine that can reduce power consumption while increasing a time required for obtaining a first copy image, a so-called first copy speed.

[0002]

2. Description of the Related Art In recent years, there has been a great demand for a copying machine to increase the first copy speed of the copying machine in order to increase the efficiency of office work. In some cases, a fluorescent lamp is used as a light source of a lighting device instead of a halogen lamp in order to reduce power consumption. By the way, fluorescent lights
It has the characteristic that the amount of emitted light greatly changes depending on the tube wall temperature. In order to obtain a stable image, the tube wall temperature must be raised to a predetermined temperature and the light amount must be kept constant. Therefore, time is required for the tube wall temperature to reach the predetermined temperature. Therefore, in order to increase the first copy speed, the fluorescent lamp is heated by a heater,
Insulation control for keeping the tube wall temperature at a temperature at which the maximum luminous efficiency can be obtained is performed from the standby time. As a result, the time required for the fluorescent lamp to reach a predetermined light amount is reduced, and the first copy speed can be increased.

[0003]

However, in a normal copying machine in which the standby time is much longer than the copying time, if the heater is constantly used to keep the fluorescent lamp warm during the standby time, the power consumption of the heater is reduced. The amount is large, and the energy saving effect of the fluorescent lamp is diminished. SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned technical problems, and to provide a lighting apparatus for a copying machine that can increase a first copy speed and reduce power consumption.

[0004]

According to a first aspect of the present invention, there is provided an illumination apparatus comprising: a fluorescent lamp as an exposure light source of a copying machine; a temperature detecting unit for detecting a fluorescent lamp temperature;
A heater for increasing the temperature of the fluorescent lamp and a fluorescent lamp
The aging of fluorescent lamps based on the amount of light when lighting under predetermined conditions
A change detecting means for detecting a change with time,
Temporal change detected based on the relationship between lamp temperature and light intensity
The minimum amount of light required for the lighting device
Temperature to set a predetermined temperature within the fluorescent lamp temperature range where
A degree setting means, and controls the heat insulating heater, a fluorescent lamp temperature, set
A heater control means for controlling the temperature to be a predetermined temperature.

According to a second aspect of the present invention, there is provided the lighting device according to the first aspect , further comprising a trigger detecting means for detecting a start of a copying operation, and the heater control means detecting a detection result of the trigger detecting means. To control the heater,
The fluorescent lamp temperature, and is characterized in that Ru is raised to set predetermined temperature.

Furthermore, the lighting device according to claim 3 is the illumination apparatus according to claim 1 or 2, aging of by Ri detected fluorescent light to the change with time detecting means reaches its end of life
The heat retention temperature controlled by the heater control means is gradually increased.

[0007] The lighting device according to claim 4 is characterized in that:
2. The lighting device according to claim 1 , wherein the temperature setting means is
Only a predetermined temperature difference from the lower limit temperature of the specified fluorescent lamp temperature range
Further setting a low temperature, wherein the heater control means
Keep the lamp temperature at the low temperature and within the allowed time
In addition, the temperature is raised to a predetermined temperature within the fluorescent lamp temperature range .

[0008]

According to the configuration of the first aspect of the present invention, when the copying machine is on standby, the fluorescent lamp can be kept at a temperature at which the minimum necessary light quantity can be obtained by the heater control means.
The time for raising the temperature of the fluorescent lamp during copying to the temperature at which the maximum luminous efficiency can be obtained (optimal tube wall temperature) can be omitted, and as a result, the first copy speed can be increased. Further, the temperature of incubation the fluorescent lamp, the low Kudekiru than the optimum tube wall temperature, it is possible to reduce the power consumption of warmth heater as compared with the case of thermal insulation of the fluorescent lamp to the optimal tube wall temperature. Furthermore, without being affected by aging,
The required light intensity can be obtained, and the first copy speed
Can be maintained at high speed.

According to the construction of the invention according to claim 2,
In addition to the effect of the invention according to claim 1, the start of the copying operation by the trigger detection means is detected, the fluorescent lamp temperature is above <br/> rise, at the start of the image copying, the fluorescent lamp is more efficient It can emit light well. As a result, it is possible to reduce power consumption of light emission of the fluorescent lamp.

According to the configuration of the invention according to claim 3,
In addition to the effect of the invention according to claim 1 or 2, the fluorescent lamp temperature can be increased as the change over time of the fluorescent lamp progresses and the life thereof approaches, so that the light emission amount of the fluorescent lamp can be increased. . Therefore, the increased amount of light can compensate for the decrease in the amount of light due to the aging of the fluorescent lamp, so that even when the aging occurs, the time for raising the fluorescent lamp temperature to the optimum tube wall temperature during copying can be reduced, As a result, a high first copy speed can be maintained.

According to the configuration of the invention according to claim 4,
Since the heat retention temperature of the fluorescent lamp can be kept lower,
Power consumption can be further reduced.

[0012]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a front external view of a copying machine provided with a lighting device according to one embodiment of the present invention. This copier is supposed to be used in a copy service shop, and includes a main body 1 and a coin insertion machine 4 installed near the main body. The coin insertion machine 4 has a coin insertion slot 41.
When a coin is inserted from here, a coin detecting unit (not shown) in the coin insertion machine 4 causes the main body 1 to be inserted.
Trigger signal described later is sent.

The main body 1 has a human body detector 13 comprising an infrared sensor or the like on the front surface thereof, and a setting operation section 16 provided with operation keys 14 and a display device 15 on the front upper surface of the main body 1 above the main body detector 13. Is provided. On the upper surface of the main body 1, a document holder 12 that can be rotated and opened and closed is provided for pressing a document placed thereon. An open / close detector 17 is provided near the document holder 12, and generates a trigger signal when the document holder 12 is opened and closed. Also,
The trigger signal is generated when the approach of a person in front of the copying machine is detected by the human body detector 13. Further, the trigger signal is transmitted to the operation key 14 by the setting operation section 16.
Also occurs when the first input is performed by touching any of the above. The display device 15 of the setting operation unit 16 can provide operation guidance to the operator and inform the operator of an abnormality. The operation key 14 allows the operator to enlarge or reduce a copy image (magnification ratio), and Copy conditions such as image density can be set.

FIG. 2 is a partial cross-sectional view of the schematic structure of the main body 1 of the copying machine. Document holder 1 on the top of the body 1
A document table 11 made of a transparent glass plate on which a document is placed is fixed below the main body 1. An illumination device 2 as a light source for exposing a document is provided below the document table 11 so as to be reciprocally movable (movable to the left and right in FIG. 2).

The lighting device 2 uses a straight tube-shaped fluorescent lamp 21 as a light source, and makes the longitudinal direction of the fluorescent lamp 21 perpendicular to the moving direction of the lighting device 2 and parallel to the document table 11. (That is, perpendicular to the paper surface in FIG. 2). The fluorescent lamp 21 extends along the longitudinal direction of the fluorescent lamp 21.
Reflector 22 having a substantially U-shaped cross-section surrounding fluorescent lamp 21
Is provided on the platen 11.

A description will be given with reference to the schematic configuration diagrams of the lighting device 2 shown in FIGS. 3 (a) and 3 (b). The fluorescent lamp 21 is of a so-called aperture type, and an aperture portion 21a for emitting light without a phosphor is formed on a part of the tube wall. Around the fluorescent lamp 21 avoiding the aperture 21a,
A warming heater 24 capable of increasing the tube wall temperature of the fluorescent lamp 21, a temperature sensor 25 detecting the temperature of the warming heater 24, and a light amount sensor 26 detecting the light amount of the fluorescent lamp 21
Are provided.

Returning to FIG. 2, the illumination device 2 can reciprocate to illuminate and scan a document (not shown) placed on the document table 11. The light reflected from the original is
The light is guided to an image forming unit 60 disposed in the center of the main body 1 via an optical system including a first mirror 51, a second mirror 52, a third mirror 53, and an optical unit 54 including lenses and the like, which moves together with the illumination device 2. As a result, an electrostatic latent image is formed on the surface of the photosensitive drum 61. In the image forming unit 60, after the electrostatic latent image is visualized, the image is transferred to a sheet supplied by the sheet feeding mechanism 62. The transferred paper is transported by a paper transport mechanism (not shown)
The sheet is conveyed to a fixing unit (not shown), and the transferred copy image is fixed. This copying operation is realized by the control unit 3 (see FIG. 4) provided in the main body 1 controlling each of the above-described units to a predetermined state in accordance with the copying conditions set via the operation keys 14 described above. You.

FIG. 4 is a block diagram of a main part of the control unit 3 described above. In FIG. 4, the control unit 3 includes a RAM and a ROM as storage means, and functions as a control center.
A PU 30 is provided. The CPU 30 is connected to a trigger detecting means 36 for detecting a start operation (trigger) of the operation of the copying machine. When a trigger is detected, a trigger signal is sent to the CPU 30. Specific triggers are insertion of coins, approach of an operator, setting of operation keys, or document holding 12
When any one of these triggers is detected, it is possible to detect that the copying by the copying machine is imminent. In addition, the above-described coin detection unit, the human body detector 13, the operation key 14, and the open / close detector 17 correspond to the trigger detection means 36 for detecting each of the triggers. If at least one of them is provided, the trigger detecting means 36 can be constituted. When the trigger detecting means 36 is provided in the main body 1 such as the human body detector 13 or the like, the coin insertion device 4 can be omitted, so that the copying machine can be used in other than a copy service shop. it can.

The CPU 30 includes a lamp lighting control circuit 32 for lighting the fluorescent lamp 21 and a light amount detection circuit 3.
The light quantity sensor 26 is connected via the first light quantity sensor 1. Light intensity sensor 2
6, the amount of light emitted from the fluorescent lamp 21 is detected, and the ratio of the supplied power to the maximum power supply to the fluorescent lamp 21 (Du
By controlling ty), the fluorescent lamp 21 can emit light at a predetermined light amount or according to the supplied power. In addition, a heater control circuit 34 for causing the heat retaining heater 24 to generate heat is connected to the CPU 30, and a temperature sensor 25 is connected via a temperature detection circuit 33. By detecting the temperature of the heat retaining heater 24 by the temperature sensor 25 and controlling the heat generation amount, the tube wall temperature can be controlled from the temperature in the vicinity of the fluorescent lamp 21. The CPU 30 also includes a photosensitive drum 61
A developing bias control circuit 35 for applying a developing bias potential is connected to the developing sleeve 63 provided in the vicinity, and the developing bias potential can be controlled according to the set copying conditions.

In this copying machine, in order to always obtain an optimum copied image in accordance with the copying conditions, the developing bias potential,
The tube wall temperature, the light amount, and the like of the fluorescent lamp 21 are controlled according to preset optimal conditions. For example, the amount of light required to obtain an optimal copied image differs depending on the copying conditions (magnification, image density, etc.), and the required amount of light increases as the magnification increases and decreases. Is "thin"
The required light amount increases as the setting is made. On the other hand, when the developing bias potential is increased, the same effect as when the light amount of the light source is increased for a copied image can be obtained, but the developing bias potential has an upper limit in order not to damage the photosensitive drum. . Therefore, the minimum required light amount required for the lighting device is
The maximum amount of light required to obtain the optimal copied image,
It can be determined from the effect of the increase in the developing bias potential up to the upper limit, and the fluorescent lamp 21 only needs to be able to emit this minimum required light amount.

In order to obtain the minimum required light amount, the fluorescent lamp 2
1 is controlled as follows. That is, a fluorescent lamp generally has a characteristic between the tube wall temperature and the amount of light shown in FIG. 5, and the amount of emitted light changes with the tube wall temperature. Wall temperature T0
At about 40 degrees (optimal tube wall temperature). Therefore, in order for the fluorescent lamp to emit a predetermined amount of light, it is necessary to raise the tube wall temperature to within a predetermined range and to keep the tube wall temperature within the predetermined range. For example, the tube wall temperature at which the fluorescent lamp can emit the minimum required light amount is determined by the fluorescent lamp at D2 in FIG.
In this case, the temperature may be within the temperature range between the temperature T2 and the temperature T6. This temperature range expands as the amount of light emission increases as the power supplied to the fluorescent lamp increases. Therefore, in this copying machine, by appropriately setting the power supplied to the fluorescent lamp 21, the tube wall temperature capable of emitting the minimum necessary light amount is set in a predetermined temperature range.
The tube wall temperature can be set to include a temperature below the optimal tube wall temperature of 40 degrees. Therefore, the fluorescent lamp 21
Can be kept at the above-mentioned low temperature (for example, the above-mentioned temperature T2), so that the power consumption for keeping the temperature can be reduced.

On the other hand, in general, the amount of light of a fluorescent lamp decreases with time. The characteristic lines D1 to D4 in FIG. 5 show the relationship between the above-mentioned tube wall temperature and the light amount with the passage of time, and change from D1 to D4 with time. Along with this change, the temperature range of the tube wall temperature at which a predetermined amount of light is obtained narrows, and the minimum temperature rises. Therefore, in this copying machine, the fluorescent lamp 21 is kept at a minimum temperature by increasing the temperature at which the fluorescent lamp 21 is kept warm, which is the lowest value of the tube wall temperature at which the fluorescent lamp 21 can emit the minimum necessary light amount, with the passage of time. The required light quantity can be compensated for the decrease in light quantity due to the change over time, and light can be emitted. When the change over time further progresses, the minimum value reaches the optimum tube wall temperature, and the fluorescent lamp 21 cannot emit the minimum required light amount soon. Therefore, it can be determined that the fluorescent lamp 21 has reached the end of its life.

Next, the above-mentioned heat retention control and life determination of the fluorescent lamp 21 will be specifically described with reference to the flowcharts of FIGS. First, in FIG. 6, when the power of the copying machine is turned on, first, the fluorescent lamp 21 is kept under a predetermined condition, for example, at an optimum tube wall temperature of 40 degrees, and a duty is maintained.
The light is turned on at 100% (step S1). At this time, the light amount sensor 26 detects the light amount of the fluorescent lamp 21,
The detected light amount value A is stored (step S2).
After detecting the light amount, the fluorescent lamp 21 is turned off (step S
3).

In step S4, the progress of the aging of the fluorescent lamp 21 is determined based on the light amount A. That is, the light amount A is compared with the preset light amount B,
It is determined from the result. The light amount B is the light amount of the fluorescent lamp measured under the same conditions as the light amount A, and is the light amount when the progress of the change with time is different.
M, stored in RAM. As described above, since the decrease in the light amount is actually detected based on the light amount A, it is possible to accurately determine the progress of the temporal change.

Hereinafter, a specific description will be given with reference to FIG. First, in the case of (detected light amount A)> (set light amount B1), the fluorescent lamp 21 is assumed to be in a state (hereinafter, “initial”) before the time-dependent change state indicated by the characteristic line D1. ) Is determined (step S5). The temperature T on the low temperature side at the intersection of the initial characteristic line D1 and the minimum required light amount
1 is set as the heat retention level of the tube wall temperature of the fluorescent lamp 21 (step S10).

If the quantity of light B1 ≧ the quantity of light A> the quantity of light B2, it is determined that the fluorescent lamp 21 is in a state of change with time shown between the characteristic lines D1 and D2 (hereinafter referred to as “middle period”). (Step S6). The insulation level of the tube wall temperature of the fluorescent lamp 21 is set to the temperature T2 (step S10). Similarly, if light amount B2 ≧ light amount A> light amount B3, fluorescent light 2
1 is determined to be in the state of temporal change shown between the characteristic lines D2 and D3 (referred to as “late stage”) (step S).
7), the insulation level of the tube wall temperature of the fluorescent lamp 21 is the temperature T3
Is set (step S10).

If the quantity of light B3 ≧ the quantity of light A> the quantity of light B4, the fluorescent lamp 21 is in a state from the latter period to the end of the life indicated by the characteristic lines D3 and D4 (referred to as “end period”), and the life is near. Is determined (step S8). Then, the approach of the service life is notified by the notification means such as the display device 15 (step S9), and the heat retaining level of the tube wall temperature of the fluorescent lamp 21 is set to the optimum tube wall temperature of 40 degrees (step S10).
At the end of this period, the setting of the heat retention level is expected to be the highest, the power consumption is expected to increase, and the service life is approaching. Therefore, the fluorescent lamp 21 that increases power consumption
It is desirable to replace the fluorescent lamp 21 in order to avoid the use of and to always maintain the copy image optimally.
In step S9, the approach of the life is notified.
Note that the light amount B3 may be changed within a certain range as needed. In this case, if the value of B3 is set to a larger value, the fluorescent lamp 21 can be replaced before the power consumption increases, and an increase in power consumption can be prevented. Further, if the value of B3 is set to a smaller value, the life of the fluorescent lamp 21 can be effectively used without waste, so that more appropriate notification according to the actual use of the copying machine can be realized.

Further, if the light amount B4 ≧ the light amount A, it is determined that the fluorescent lamp 21 has reached the end of its life (step S1).
1) Lifetime processing such as notification of the life determination by the notification means such as the display device 15 is performed (step S1).
2). Next, a description will be given with reference to FIG. In accordance with the insulation level of the tube wall temperature of the fluorescent lamp 21 determined in the above step S10, the insulation heater 24 is controlled, and the insulation control is performed so that the tube wall temperature of the fluorescent lamp 21 is maintained at the above insulation level. (Step S13). In addition, if the tube wall temperature is within a predetermined heat insulation range having the lower limit of the determined heat insulation level as a lower limit, for example, between temperatures T2 and T6 on the characteristic line D2, the heat insulation control may be omitted. In this case, even when the tube wall temperature rises when the fluorescent lamp 21 is turned on or at a high temperature, the power consumption for forcibly lowering the tube wall temperature can be reduced. , Light emission can be performed with higher efficiency, and power consumption can be further reduced.

In step S14, when the above-mentioned trigger is detected, it is determined that the image is about to be copied, and the temperature of the tube wall of the fluorescent lamp 21 is changed from the state in which the temperature was kept in step S13 to the optimum tube wall. The temperature is changed and set to 40 degrees. Along with this, when heating or the like is performed by the warming heater 24 and image copying is performed, the tube wall temperature becomes the optimum tube wall temperature (step S15). When the print key of the operation key 14 is pressed in this state (step S16),
A predetermined number of continuous copies are made, and the temperature is controlled to be kept at the optimum tube wall temperature during copying (steps S17 and S18). As described above, by setting the tube wall temperature of the fluorescent lamp 21 to the optimum tube wall temperature at the time of copying, the fluorescent lamp 21 can emit light with maximum efficiency, so that power consumption during light emission can be reduced.

A predetermined time after the end of the trigger detection,
For example, after the elapse of 5 minutes, the temperature is returned to the heat retaining level of the tube wall temperature of the fluorescent lamp 21 determined in step S10, and the heat retaining control is performed (step S19). Since the trigger detecting means 36 may detect only the start time of the copying operation, the completion of the copying operation is estimated after a lapse of a predetermined time. As a result, it is possible to prevent the time of the heat retention control at the optimum tube wall temperature from becoming unnecessarily long, and to suppress an increase in current consumption.

According to the embodiment of the present invention, since the fluorescent lamp 21 is kept at a predetermined temperature lower than the optimum tube wall temperature during standby, the power consumption of the heater 24 can be reduced. Further, the fluorescent lamp 21 can emit the minimum required light amount required for the illumination device 2 at the time of copying even at the predetermined temperature, so that time for raising the tube wall temperature can be omitted, and the first copy speed can be reduced. Can be faster. Further, the fluorescent lamp 21 is changed in the heat retention control based on the decrease in light amount due to its aging, so that the fluorescent lamp 21 can obtain the minimum required light amount without being affected by the aging, and the first copy speed can be reduced. High speed can be maintained.

In the embodiment of the present invention, step S1
The lighting of the fluorescent lamp 21 was performed under the conditions of 100% duty and a tube wall temperature of 40 degrees, but is not limited to this condition. For example, if the operation is performed under the condition of lower tube wall temperature and duty, the power consumption can be reduced. Further, in the embodiment of the present invention, the heat retention control is performed until the copying is completed. However, the present invention is not limited to this. For example, the temperature is controlled only for the first copy, and the temperature of the second and subsequent copies increases due to the heat generated by the fluorescent lamp 21 itself. Therefore, the temperature control may be omitted as described in step S13. In this case, power consumption can be further reduced.

Further, in the embodiment of the present invention, the heat retaining level of the tube wall temperature of the fluorescent lamp 21 is always set to a temperature at which the minimum amount of emitted light can be obtained, but is not limited to this. For example,
It is also possible to set the temperature (TL) lower by a predetermined temperature difference than the temperature (TH) at which the minimum light emission amount is obtained. The predetermined temperature difference (TH─TL) is a temperature difference that can increase the tube wall temperature from a low temperature (TL) to a predetermined temperature (TH) within a time allowed by the heat retention control.
In this case, the heat retention level can be kept lower, so that the power consumption of the heat retention control can be further reduced.

Further, if the light amounts B1 to B3, which are the criteria for the determination in step S4 of the embodiment of the present invention, are set in more steps, the temperature control can be more finely controlled and the power consumption can be further reduced. be able to. Further, in the embodiment of the present invention, the heat retention level is set to the optimum tube wall temperature after the end period determined to be the life, but the setting of the heat retention level after this end period is not limited to the optimum tube wall temperature. For example,
The heat retention level may be set to a temperature that is higher than the temperature T3 and lower than the optimum tube wall temperature, and at which it is not desired to further raise the heat retention level. In this case, power consumption can be suppressed according to the set heat retention level.

In the embodiment of the present invention, step S1
In 5, the heat retention level of the tube wall temperature of the fluorescent lamp 21 is changed to the optimum tube wall temperature, but this processing can be omitted. In this case, the trigger detection means 36 and steps S19 and S14 can be omitted at the same time, and the configuration and control can be further simplified. Further, since the time for keeping the heat retaining temperature of the fluorescent lamp 21 lower than the optimum tube wall temperature can be made longer, the power consumption due to the heat keeping can be reduced more than in the above embodiment.

In the embodiment of the present invention, step S4
The progress of the temporal change of the fluorescent lamp 21 is determined by comparing the detected light amount A with a preset light amount B, but can be realized by other methods. For example, a timer that can measure the elapsed time from the start of use of the fluorescent lamp 21 may be provided, and the timer may be determined to be an initial period, a middle period, etc. until the elapsed time reaches a predetermined time. In this case, the processing in steps S1 to S3 can be omitted, and the power consumption due to the lighting when the power is turned on can be reduced. Also, depending on the frequency of use of the copying machine, the actual time-dependent change may be more advanced than the assumed time-dependent change corresponding to the set predetermined time. It is more desirable to perform the heat retention control at the point of securing the first copy speed.

In addition, various design changes can be made without changing the gist of the present invention.

[0038]

According to the first aspect of the present invention, the temperature of the fluorescent lamp is maintained at a temperature at which the minimum required light amount is obtained when the copying machine is on standby, so that the time required to raise the temperature to the optimum tube wall temperature during copying is eliminated. As a result, the first copy speed can be increased. Further, it is possible to Runode be kept warm fluorescent light at a temperature lower than <br/> optimum tube wall temperature than would be kept at the optimum tube wall temperature, to reduce the power consumption of the heat insulating heater. In addition, it is affected by aging.
The minimum required light intensity can be obtained without
Peace speed can be maintained at high speed.

According to the second aspect of the invention, in addition to the effect of the first aspect, the start of the copying operation is detected and
By increasing the temperature of the fluorescent lamp, the fluorescent lamp can emit light efficiently at the time of image copying, so that the power consumption of light emission of the fluorescent lamp can be reduced. According to the invention of claim 3, in addition to the effect of the invention according to claim 1 or 2, enough time course of fluorescent light proceeds by raising the fluorescent lamp temperature, emission increases with increasing temperature The amount can compensate for a decrease in the amount of light due to the temporal change of the fluorescent lamp. As a result, even when there is a change over time, the time for raising the fluorescent lamp temperature to the optimum tube wall temperature during copying can be shortened, so that a high first copy speed can be maintained.

According to the fourth aspect of the present invention, the fluorescent lamp temperature
, The power consumption can be further reduced .

[Brief description of the drawings]

FIG. 1 is a front external view of a copying machine to which a lighting device according to an embodiment of the present invention is applied.

FIG. 2 is a front sectional view of a main part of the main body of the copying machine.

3A and 3B are schematic configuration diagrams of a lighting device, where FIG. 3A is a front view and FIG. 3B is a side view.

FIG. 4 is a block diagram of a main part of a control unit of the copying machine.

FIG. 5 is an explanatory diagram of characteristics of a fluorescent lamp and heat retention control.

FIG. 6 is a flowchart of heat retention control.

FIG. 7 is a flowchart of the heat retention control continued from FIG. 6;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Copier main body 2 Illumination device 21 Fluorescent lamp 24 Heat retention heater 25 Temperature sensor (temperature detection means) 34 Heater control circuit (heater control means) 36 Trigger detection means Step S1-4 Step change detection means Step S5-8, 10, 13 Heater control means Step S8, 11 Life determination means Step S14-15 Light emission temperature increasing means

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shuichi Ikuno 1-2-28 Tamazo, Chuo-ku, Osaka-shi, Osaka Inside Mita Kogyo Co., Ltd. No. 28 Mita Kogyo Co., Ltd. (56) References JP-A-64-2077 (JP, A) JP-A-61-216298 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03B 27/54 G03G 15/04

Claims (4)

(57) [Claims] 1. A fluorescent lamp as an exposure light source of a copying machine, a temperature detecting means for detecting a fluorescent lamp temperature, a warming heater for increasing the fluorescent lamp temperature, and a light amount when the fluorescent lamp is turned on under a predetermined condition. Based on fluorescence
A time-dependent change detecting means for detecting the time- dependent change of the lamp, and a detection based on the relationship between the fluorescent lamp temperature and the light amount accompanying the time-dependent change
The minimum required for the lighting device according to the known aging
The required amount of light must be within the fluorescent lamp temperature range
A lighting device comprising: temperature setting means for setting a temperature; and heater control means for controlling a warming heater to control a fluorescent lamp temperature to a predetermined temperature. apparatus. 2. The lighting device according to claim 1 , further comprising: trigger detection means for detecting a start of a copying operation , wherein said heater control means controls a heat retaining heater in response to a detection result of said trigger detection means, Set the fluorescent lamp temperature to
Lighting apparatus characterized by Ru is raised to a predetermined temperature. 3. A lighting device according to claim 1 or 2, time-varying due Ri detected fluorescent light to the change with time detecting means
A lighting device characterized in that the warming temperature controlled by the heater control means is increased as the lifetime approaches the life . 4. The lighting device according to claim 1 , wherein the temperature setting means is configured to determine a lower limit temperature of the determined fluorescent lamp temperature range.
A temperature lower than the temperature by a predetermined temperature difference, and the heater control means sets the fluorescent lamp temperature to the low temperature.
Hold the lamp within the temperature range of the fluorescent lamp within the allowable time.
A lighting device characterized by raising the temperature to a certain temperature .