JPH0766154B2 - Method and apparatus for preventing light source deterioration of exposure apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a light source used in an exposure apparatus such as a contact printing machine for plate making, a copying camera for plate making, etc. It is about.

<Prior Art> A halogen light bulb is a kind of incandescent light bulb, but is different from a general incandescent light bulb in that a halogen element such as iodine, sulphur, or chlorine is enclosed in a bulb in the form of a single substance or a compound.

That is, as shown in FIG. 2, the halogen element enclosed in the tube 2, for example, iodine I, is combined with the tungsten W evaporated from the filament 3 to form the tungsten halide WI.
₂ , the tungsten halide WI ₂ is decomposed by the heating of the filament 3 to be separated into tungsten W and halogen I, and the tungsten W returns to the filament 3 again.

In other words, by repeating the halogen cycle repeatedly,
The advantage of the halogen bulb is that it prevents the phenomenon of deterioration over time that is seen in general incandescent bulbs in which tungsten W adheres to the tube wall 2a and turns black, and the light intensity is stable over a long period of time.

However, in the past, for example, in a contact printing machine for a bright room, the halogen bulb has not been used as a light source.

The emission spectrum of this halogen bulb includes the photosensitive wavelength range (around 400 nm) of the sensitive material for bright room where yellow light is safe light, and has an originally practical light emission amount as a light source of the contact printing machine for the bright room. However, since the lighting time in the exposure apparatus is relatively short (2 seconds to 10 seconds or less), the halogen cycle does not circulate sufficiently, and tungsten W does not flow in the lowest temperature portion of the bulb. Adhere to the tube wall, and the tube wall is blackened, causing a sharp decrease in the light amount.

Therefore, conventionally, a metal halide lamp or the like has been used.

<Problems to be Solved by the Invention> On the other hand, the metal halide lamp has to be provided with a cooling device, a preliminary lighting circuit, an explosion-proof interlock circuit, and the like, which causes a problem of high cost as a whole.

The present invention has been made in consideration of such circumstances, and makes it possible to use a halogen light bulb as an exposure light source whose lighting time is relatively short, that is, the life of the halogen light bulb is significantly increased. The task is to extend.

<Means for Solving the Problems> In order to solve the above problems, the present invention is configured as follows.

That is, the intermittent lighting integrated value of the halogen light bulb which is the light source for exposure is counted, and when the intermittent lighting integrated value reaches a predetermined value, the halogen light bulb is continuously lit for the halogen cycle recovery time. A deterioration prevention method and apparatus.

<Function> For example, when a halogen lamp of 1 KW is used and intermittent lighting is performed for 5 to 10 seconds / time about 800 times to 1000 times, the tungsten halide WI ₂ begins to slightly adhere to the tube wall.

In the present invention, for example, by observing the time when such a blackening phenomenon is recognized, the halogen bulb is continuously turned on for a required time, for example, for 5 minutes to raise the temperature of the tungsten halide adhering to the tube wall to perform the halogen cycle. Circulate well. As a result, the tungsten halide is released from the tube wall, and the light quantity of the halogen bulb is restored.

<Example> FIG. 1 is a schematic view showing a case where the present invention is applied to a contact printing machine for plate making.

This contact printing machine includes a box-shaped machine frame 10, an exposure device 11, and a machine frame.
A translucent plate 20 horizontally supported on the upper surface of 10 via a support frame 10a.
A film original plate S and a photosensitive material P, which are provided with an overlay sheet 21 stretched over the translucent plate 20 so as to be able to be unwound, and an exhaust means 22, and are stacked on the translucent plate 20. Is covered with an overlay sheet 21, and the gap between the translucent plate 20 and the overlay sheet 21 is exhausted by the exhaust means 22 to bring the film original plate S and the photosensitive material P into close contact with each other, and the light source 1 is turned on to produce the original film original plate S. The image is printed on the photosensitive material P.

The exposure device 11 is provided with a light source box 12 arranged in the lower part of the machine frame 10 and a control circuit 13 for controlling blinking of the halogen bulb 1 which is a light source in the light source box 12. Incidentally, reference numeral 4 is a concave reflecting mirror,
Reference numeral 5 is a condenser lens.

The control circuit 13, baking lighting time T _E, the lighting time for a given halide cycle lighting start corresponding value N and the light quantity recovery T _R
Operation panel 14 for setting and inputting etc., and microcomputer 15
The halogen lamp 1 has a burn-in lighting circuit 16, a light amount recovery lighting circuit 17 for the halogen lamp 1, and a counter 18 for counting the intermittent lighting frequency integrated value T _N of the halogen lamp 1. The counter 18 integrates the intermittent lighting frequency. When the value T _N has reached the above N, it is displayed on a display means (not shown) on the operation panel 14 or a buzzer is used to warn the operator. It is configured to only continuous lighting set time T _R.

That is, as shown in FIG.
When T _E , a predetermined halogenation cycle lighting start correspondence value N, and a lighting time T _R for light intensity recovery are set and the start button is pressed (step S ₁ ), first, in step S ₂ , the translucent plate 20 and the overlay are overlaid. Exhaust between the sheets 21 starts, and the vacuum adhesion between the film original plate S and the photosensitive material P is started. When the predetermined time has elapsed from the contact start, then the exposure in step S ₃ by baking time T _E necessary for the film original plate S is made, vacuum contact is released between the film original plate S and sensitive material P at Step S ₄ after completion of exposure Then, in step S ₅ , the baking work is finished, and the baking work is repeated. Meanwhile, as counter 18 of the step S ₃₁
Then, the number of times the halogen bulb 1 is turned on is integrated.

The integrated value T _{N of the} counter 18 is the predetermined halogenation cycle lighting start time corresponding value N preset in the operation panel 14.
Whether a match is determined in the step S ₃₂ and, subsequently enables baking operations back to the initial state of the baking operations of steps S ₁ if it does not match, the counter in step S ₃₃ if a match 18 Reset the integrated value T _N of
_A warning is displayed at ₃₄ , or a buzzer alerts the operator. Operator Step S ₃₅ based on this
In order to recover the light quantity as described above, the light is continuously lit for a preset lighting time T _R.

Further, instead of the operator is continuously turned on every display, for example, intermittent lighting integrated value T _N based on the reset signal of the counter 18 for counting the amount recovered lighting circuit 17 as in step S ₃₃ of the flowchart of FIG. 4 ( It is also possible to operate so as to automatically turn on continuously (Fig. 1).

By the way, the predetermined halogen lighting start corresponding value N
As is the numerical value corresponding to the intermittent illumination count of approximately be for example 800 to 1000 times observed blackening due to adhesion of tungsten halide to the bulb, as the amount recovered lighting time T _R, the tube is 250 ° C. or higher It is heated for about 2 to 5 minutes, which is necessary for sufficiently recovering the halogen cycle.

FIG. 3 is a graph showing the light quantity recovery state of the halogen lamp. That is, the horizontal axis represents the number of intermittent lighting and the vertical axis represents the amount of light, and each time the number of intermittent lighting reaches 1000, the halogen lamp is continuously lit for 5 minutes, and the state of recovering the amount of light is shown by the solid line. Is.

The solid line G ₁ indicates the amount of light (Lux) in the visible light region as G ₂
Indicates the light amount (Lux) in the blue light region, and broken lines g ₁ and g ₂ indicate the case where the light amount recovery lighting is not performed.

As is clear from FIG. 3, when the light intensity recovery lighting is not performed, the light intensity decreases rapidly, and when the light intensity recovery lighting is performed, it is possible to maintain a stable light intensity (80% or more) for a long period of time. I can.

In the above example, the contact printing machine for plate making was illustrated,
The present invention is not limited to this, and can be widely implemented in a copying machine, a plate-making camera, etc. in which the lighting time is set to a relatively short time.

In addition, a predetermined halogen-cycle lighting start corresponding value N,
It is not necessary to say that the light intensity recovery lighting time T _R can be set by appropriately changing it according to the type of halogen lamp.

Note that the intermittent lighting integrated value N _N may be an integrated value of the intermittent lighting time, for example, 7 seconds × 1000 times (≈2 hours), instead of the integrated value of the intermittent lighting times as in the above embodiment.
In this case, the continuous lighting time is about 5 minutes.

<Effects of the Invention> As is apparent from the above description, in the present invention, when the intermittent lighting integrated value reaches the predetermined value and the blackening phenomenon is recognized in the bulb, the halogen bulb is continuously lit for the predetermined time, and the halogen Since the cycle is circulated sufficiently, the light quantity of the halogen bulb can be restored.

As a result, the halogen light bulb can be used for a long period of time as an exposure light source whose lighting time is relatively short.

Therefore, compared with the case where a metal halide lamp or the like is used, a significant cost reduction can be achieved, and maintenance work such as light source replacement can be facilitated.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an apparatus of an embodiment of the present invention, FIG. 2 is a schematic diagram for explaining a halogen cycle, FIG. 3 is a graph showing a light amount recovery of a halogen bulb according to the present invention, and FIG. It is a flow chart which shows operation of an example device. 1 ...... halogen bulb, 11 ...... exposure device, 16 ...... lighting circuit, 18 ...... counting means (counter), T _N ...... intermittent lighting integrated value, N ...... halogenated cycle lighting start corresponding value, T _R ... …
Halogen cycle recovery time (light intensity recovery lighting time).

Claims (2)

[Claims] 1. An intermittent lighting integrated value of a halogen light bulb as an exposure light source is counted, and when the intermittent lighting integrated value reaches a predetermined value,
Method for preventing deterioration of light source of exposure apparatus, characterized by continuously turning on halogen bulb for halogen cycle recovery time 2. A lighting circuit for intermittently lighting a halogen bulb,
Counting means for counting the intermittent lighting integrated value of the halogen bulb,
A storage means for storing in advance a lighting start corresponding value for the halogenation cycle as a value corresponding to the intermittent lighting integrated value, a means for comparing the intermittent lighting integrated value and the halogenation cycle lighting start corresponding value, and the intermittent lighting integrated value When the value reaches the value corresponding to the halogenation cycle lighting start value, the judgment means that outputs the halogenation cycle lighting start signal and the light intensity recovery time determined by the characteristics of the halogen bulb are stored, and the halogen bulb is continuously illuminated for the light intensity recovery time. A light source for an exposure apparatus, wherein the determination means outputs a halogenation cycle lighting start signal to display continuous lighting start or activate the continuous lighting circuit. Deterioration prevention device