JPH0459748B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heating device for a discharge lamp, and more particularly to a heating device for a discharge lamp when a fluorescent lamp discharge lamp is used as an exposure lamp for a copying machine. be.

As is well known, the light output of discharge lamps such as fluorescent lamps changes greatly depending on the environmental temperature, and generally the maximum light output can be obtained when the lamp tube wall temperature is around 40℃. can.

Therefore, when using a discharge lamp as an exposure lamp for a copying machine, warm the discharge lamp with a lamp heater until the lamp tube wall temperature reaches around 40℃, and then
It is necessary to control the temperature so that high light output can be obtained at all times.

Therefore, in general, in a low-temperature environment or when starting up a copying machine, the discharge lamp is heated in advance before copying operation begins, thereby preventing a drop in the exposure amount.

FIG. 1 is a schematic sectional view of a conventional heating device for a discharge lamp, and FIG. 2 is a diagram for explaining the arrangement of heater elements of the conventional heating device. As is clear from the figure, conventionally, a single heater element 4 is disposed in an insulating member 3 to form a lamp heater section 2, and a thermostat 5 closely disposed on the back surface of the lamp heater section 2 controls the heater element. The temperature of the discharge lamp 1 was controlled by controlling the current flowing through the discharge lamp 4 on and off.

However, in the above-mentioned device,
When heating the discharge lamp 1, the amount of overshoot of the tube wall temperature of the discharge lamp 1 tends to be large with respect to the reference temperature, and the temperature may temporarily rise to a temperature considerably higher than the reference temperature.

As a result, the light output of the discharge lamp 1 fluctuates, and the insulating material of the lamp heater section 2 has problems in terms of heat resistance.

Further, when the large electric power applied to the heater element 4 is controlled on and off by the thermostat 5, problems such as burnout of the contacts of the thermostat 5 occur.

The object of the present invention is to eliminate the drawbacks of the prior art,
By reducing the amount of overshoot during heating of the discharge lamp, stabilizing the light output of the discharge lamp, and preventing abnormal temperature rise of the insulating member, furthermore, by reducing the power consumption of each individual heater element, the thermos It is an object of the present invention to provide a heating device for a discharge lamp that reduces the load on control elements such as contacts and eliminates burnout of contacts.

In order to achieve the above object, the present invention connects a plurality of heater elements in parallel to make the total power consumption the same as the conventional single heater element power consumption, and to reduce the power consumption of some of the heater elements. Focusing on the fact that if temperature control is performed using a heater element, the load on the thermostat can be lowered without lowering the heating effect, a plurality of heater elements are connected in parallel as a heating device for a discharge lamp. The feature is that the element is controlled in at least two different temperature ranges.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 3 is a diagram for explaining the arrangement of heater elements of a heating device for a discharge lamp according to an embodiment of the present invention, and FIG. 4 is a circuit diagram of the embodiment.

As shown in FIG. 3, two heater elements, a first heater element 6 and a second heater element 7, are provided in parallel in substantially the same position in the insulating member 3.

Furthermore, as shown in FIG. 4, a first thermostat 8 is connected to the first heater element 6, and a second thermostat 9 is connected to the second heater element 7.

The first and second thermostats 8 and 9
are set to turn on and off the first and second heater elements 6 and 7 in different temperature ranges.

FIG. 5 is a diagram showing the relationship between the heating time of the discharge lamp 1 and its tube wall temperature in this embodiment. In the figure, the horizontal axis represents the heating time [t] of the discharge lamp, and the vertical axis represents the tube wall temperature [° C.] of the discharge lamp.

In addition, the solid line in FIG. 5 indicates the configuration of this embodiment, in which the two heater elements of the discharge lamp are connected in parallel, and each of them is controlled to turn on and off at different temperature ranges. The graph shows the change in tube wall temperature under the following conditions. For comparison, the broken line shows the transition of the tube wall temperature in the conventional example when the single heater element described above is arranged.

Normally, immediately after the copying machine is powered on or in a low-temperature environment, the discharge lamp 1 is in a low-temperature state as described above, but current is not allowed to flow through the first and second heater elements 6 and 7. As a result, the discharge lamp 1 is rapidly warmed up.

Then, when the tube wall temperature of discharge lamp 1 rises to a temperature 5 to 10 degrees Celsius lower than the normal use control range (5th
At point (a) in Figure A), for example, the second thermostat 9, which has a lower set temperature, is turned off.

After that, heating and temperature control are performed only by the first thermostat 8 and the first heater element 6, which have a high set temperature (normally used temperature control range).

That is, when the tube wall temperature of the discharge lamp 1 reaches, for example, around 40°C, which is set as the reference point (the fifth
At point b in the figure), the first thermostat 8 is turned off, cutting off the power supply to the first heater element 6.

When the power supply to the first heater element 6 is cut off, the tube wall temperature does not rise much further than the reference point (40°C), and as shown in Fig. After that, it starts to gradually decline.

When the tube wall temperature gradually decreases and falls slightly below the reference point (time point c in FIG. 5), the thermostat 8 is turned on again and the first heater element 6 is turned on.
energization is resumed.

When the power supply to the first heater element 6 is resumed, the temperature of the tube wall of the discharge lamp 1 increases again, as is clear from FIG. 5. When the tube wall temperature reaches the vicinity of the reference point (time point d in FIG. 5), the first thermostat 8 is turned off again to cut off the power supply to the first heater element 6.

Thereafter, the temperature control by the first heater element 6 is performed by repeating the same operation.

As a result, it becomes possible to perform stable temperature control.

As described above, the present invention provides a heating device for a discharge lamp in which a plurality of heater elements are arranged at approximately the same position and connected in parallel, the plurality of heater elements are divided into at least two groups, and each group is connected to each other. Since the temperature is controlled in different temperature ranges, by applying full power to multiple heater elements immediately after the power is turned on, the discharge lamp can be quickly warmed up as before, and
In the vicinity of the normal operating temperature, it is possible to use a low-power heater using only a part of the heater elements, and to control the temperature by a control element connected to the heater elements, which has the following advantages.

More stable temperature control can be achieved, the amount of overshoot can be reduced, and the light output of the discharge lamp can be stabilized.

Temporary abnormal temperature rise of the insulating member of the lamp heater section can be prevented.

Since the load on each thermostat, which controls on-off the current flowing through the heater element, is also reduced, there is no risk of burnout of the contacts.

Since the at least two groups of heater elements are arranged at substantially the same position, it is possible to always perform substantially uniform temperature control over the entire discharge lamp, and the light output can be stabilized throughout the discharge lamp. .

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of a conventional heating device for a discharge lamp, FIG. 2 is a developed view for explaining the arrangement of heater elements of the conventional heating device, and FIG. 3 is a schematic cross-sectional view of a conventional heating device for a discharge lamp. FIG. 4 is a developed diagram for explaining the arrangement of heater elements of a heating device for a discharge lamp, FIG. 4 is a circuit diagram of the above-mentioned embodiment, and FIG. 5 is a diagram showing the relationship between heating time of a discharge lamp and its tube wall temperature. It is a diagram. 6, 7... Heater element, 8, 9... Thermostat.

[Claims]

1. The core is made of a metal with lower electrical resistance than pure lead and has a tensile strength of 2.2 Kg/mm2 or ^more after 3 days of aging.
And tensile speed (cross head speed) 10mm/
A positive electrode is constructed in which a core coating layer made of a lead alloy with an elongation rate of 28% or less in seconds is applied to form a side conductor column, and a connecting part made of pure lead is provided at at least one part of the side conductor column. A lead-acid battery characterized by having a side conductor connected to a plate. 2. Claim 1, wherein the connecting portion is an inter-column connecting portion that connects side conductor column portions.
Lead-acid batteries as described in Section. 3. The lead-acid battery according to claim 1, wherein the connecting portion is a return plate connecting portion that connects the positive electrode plate and the side conductor column portion. 4. The lead-acid battery according to claim 1, wherein the side conductor column portion is coated with Hypalon on the core coating layer and is further covered with a polyester tube. 5. The lead-acid battery according to claim 1, wherein the side conductor column portion is coated with polyisobutylene on its core coating layer. 6 Claim 2, characterized in that the surface of the connection between the pillar parts is coated with polyisobutylene.
Lead-acid batteries as described in Section. 7 The surface of the connection part of the return electrode is coated with polyisobutylene.