JPS59177896A - Illuminator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a lighting device including a light source that emits light by receiving power from a power supply means.

BACKGROUND OF THE INVENTION The above-mentioned illumination device shown in FIG. 1 is known, and the illumination device in this case is used as a 4Φy component of a copying machine. In the same figure, two 7 lash lamps 6 are arranged facing each other on the lower side of the opposite end of the contact glass 2 on which the original 1 is placed, parallel to the end and having almost the same length as the end. It is being A reflector plate 4 is placed behind each lamp B, and the contact glass 2 is reflected by the direct light from the lamp 6 and the reflected light from the reflector plate 4.
is evenly illuminated. For this reason, the shape of the reflecting plate 4 is generally made into a parabolic shape in many cases.

The two lamps 6 each have a trigger electrode 5 at one end, and the electrodes at both ends of the lamps are connected in series to the power supply circuit 6. lamp 3
emits light by adding electric current to the trigger electrode 5.

An optical image of the document 1 illuminated by the light from the lamp filter is formed on the photoreceptor 8 through the lens 7, forming an electrostatic latent image on the photoreceptor 8.

In the conventional lighting device that operates as described above, a flash lamp 6 with a long distance between electrodes is used as a light source, so a high constant 1]- must be added between both terminals, and therefore the power supply circuit A step-up transformer (not shown) is housed inside 6. As described above, since a high voltage is applied to the lamp 3, from the viewpoint of safety, the wires used as the power supply path must be thick wires with high insulation, which results in cost reduction. Invite high.

Furthermore, in order to eliminate uneven illuminance on the contact glass 2, the shape of the reflector 4 must be complicated.

The object of the present invention is to provide a lighting device that easily reduces unevenness in illuminance, operates at low voltage, is highly safe, and is low in cost. shall be.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to drawings showing embodiments thereof.

In FIG. 2, the contact crow 2 on which the original 1 is placed
A plurality of flash lamps E1 to E2 are arranged below the contact glass 2, corresponding to each side of the contact glass 2.

FIG. 6 is a plan view taken along arrow m in FIG. 2, and clearly shows the arrangement 6' of the flash lamps E1 to E22Q).

As shown in FIG. 4, the flash lamps E1 to EZ2 have two electrodes 9 and 10, a power supply line 12 for applying a voltage between these electrodes, and a trigger electrode 16.
, and a trigger line 14 for applying voltage to the liquid electrode.

In FIG. 2, the power line 12 of each flash lamp E1-E2□ is connected to a control circuit 15, or a power charging capacitor 16 is disposed in its path. Further, the trigger line 14 is controlled by a control circuit 15 [・Reca control circuit 17
Contact. The trigger control circuit 17 is the bottom of the command from the control circuit 15, and the flash lamps E1 to
Selectively trigger E22. For example, in FIG. 6, when all the lamps El to E22 are triggered, and when the lamp E4 + "'5 surrounded by a broken line is triggered,
+ E8 r E9 + "'12 + E13.Hereinafter, the lamps surrounded by the broken line will be referred to as group A lamps, and the other lamps will be referred to as group 3 lamps. It's called a lamp.

When only the lamps in group A are turned on as in Iluni, only those lamps emit light, so the contact glass 2 is partially illuminated as shown by the dashed line in Figure 6, so the small When copying a size original, this illumination method θ is sufficient.

In Fig. 2, a reflector plate 18 is arranged 6 on the back side of each of the flash lamps E1 to E2□ with respect to the contact glass 2, but the figure shows only the one corresponding to lamps E21 + E22, and The antiq- version of J2 is omitted for convenience.

FIG. 5 shows a specific configuration of the main parts of the control circuit 15 in FIG.

The control circuit 15 includes a manual switch 19 , a rectifier circuit 21 , a group A pump power supply switch 22 , and an 8 group lamp power supply switch 26 . The input switch 19 is a triac 2 connected between the rectifier circuit 21 and the commercial power supply E.
4 and an ignition circuit 25 that triggers the triac 24.
and has. The ignition circuit 25 starts the triac 2 by receiving charging start fg No.
Try 4.

The A group pump supply switch 22 connects the rectifier circuit 21 to the A
It has a 5CR1 placed in the power supply path leading to the group pump 26 and an ignition circuit 27 that triggers the 5CR1. 16 is to be charged. 5CR1 is triggered by receiving N. B R' (The lamp power supply switch 26 has a 5CR2 placed in the power supply path leading from the rectifier circuit 21 to the 8 group lamp 27, and an ignition circuit 28 that triggers the 5CR2. '8 is the capacitor 1 of the 8 group lamp from the central control unit as described in
Signal B indicating that 6 should be charged. 5C by receiving N
Trigger R2.

In addition to the illustrated elements, the control circuit 15 includes A
Swamp charging signal A. N and B4'? 1 lamp charging signal B. Trigger control circuit 17 (Fig. 2)
The elements for sending commands to the computer are omitted in the diagram.

/1N: The lighting device according to the embodiment has the following two configurations, and operates as described above. First, either full copy or partial copy is selected in the rewriting central control rilil device t:j, and depending on the result, A is sent to the control circuit 15. N signal and B. N signal or A. Only N messages are sent. Now, if the full-scale copy mold is selected,
The AoN signal and the BON4A signal are sent to the control circuit 15, so that both power supply paths from the rectifier circuit 15 to the A-group pump 26 and the 8-group lamp 27 are electrically connected.

Therefore, the charging start signal is then output. When N is sent, the power supply path from the commercial power source E to the rectifier circuit 21 is closed, and after the alternating current is rectified by this rectifier circuit 21, it is sent to the A group pump 26.
And each capacitor connected to each lamp of the 8 group lamps 27 is charged. Reference number 29 is a current limiting impedance placed after the rectifier circuit 21. When the charging of the capacitor 16 is completed, the trigger control circuit 17 (FIG. 2) outputs the lamps E1 to E22 at an appropriate timing.
A trigger signal is sent to each of the trigger electrodes, whereby the lamps E1 to E22 emit light, and the original on the contact crow 2 (FIG. 2) is instantly illuminated.

When the document 1 or small size is on the contact glass 2, if all the lamps are used in vain, the result will be 6%, so only the necessary lamps are activated (partial copying). In this case, only "ON" is selected, and therefore only the circuit from the rectifier circuit 21 to the A group pump 26 in FIG. 5 is closed. When the trigger electrode of the lamp is triggered in this state, An :0 lamp 26 (lamp E4 + ” in Figure 6)
'5 + E8 + E9 + E12 + gt3) only emits light, and only the desired area or 1 ((1) is illuminated, so
Very economical. In addition, in the above partial copy mode, the lamp that should be triggered when the lamp emits light is A.
It may be only a group of lamps, or it may be both A and B groups of lamps. Even if the lamps of group B are triggered, the lamps of group 8 will not emit light because the capacitors of the lamps of group B are not charged.

As can be seen from the above explanation, this embodiment is suitable for commercial use.
5 source is directly rectified without boosting the voltage and charged to capacitor 16.
6 is at most about 14 times the commercial power supply 'iW LJ'. Therefore, the lamps E1 to E22 that emit light using the rechargeable type 11 of the capacitor 16 must emit light when a voltage higher than 141j'1 of the commercial '1a whale' is applied. lI'I! between the electrodes as in the conventional case.
A lamp with a long conductor cannot emit light at such a low voltage, so as in this embodiment, the lamp used to illuminate the original is placed between the electrodes hq! When a plurality of lamps with low mp are used, each lamp can be made to emit light with a small voltage. In other words, 4-1 is achieved by appropriately narrowing the distance between the electrodes of the flash lamps E1 to E22 so that the lamps can emit light even when the electric current of 1.4·1jη or less is applied to the commercial power supply. A sufficient illumination effect can be obtained without boosting the commercial '1u source. That is, the step-up transformer, which was an essential component in conventional devices, can be eliminated.

In addition, since the electrode voltage is low, there is no need to take special safety measures for electric wires, etc., and therefore there is no need to worry about high costs.

In order to uniformly illuminate the original 1 on the contact glass 2, the light from the lamps E1 to E22 must be illuminated by 11
1 to B22 can be individually moved and their positions adjusted, so it is possible to provide illumination with extremely little unevenness in illuminance.

Furthermore, as mentioned above, the distance between the electrodes of the lamps E1 to E22 is small, so the impedance when the lamps emit light is low.
Therefore, the light emission time of the lamp can be shortened. A short lamp emission time means that the exposure time of the light image on the photoreceptor based on the light emission will be shorter, and as a result, the distance traveled by the photoreceptor during the exposure time will be shortened. Since it can be pressed in this way, high-resolution images can be obtained.

In the above embodiment, a bulb type lamp as shown in FIG. 4 was used as the flash lamp, but the bulb type lamp as shown in FIG.
You may use the type. In the figure, Fuso 61. Ro2
is the electric (1 λ, 9': J No. 33 or trica') u pole opposite to HH.

Furthermore, the lighting device according to the present invention can be applied not only to copying machines but also to other devices such as facsimile machines.

Effects As in Song Yi 1-, according to the present invention, there is less unevenness in illuminance.
A lighting device with high safety and low cost can be obtained.

[Brief explanation of drawings]

FIG. 1 is a perspective view of essential parts of a copying machine showing an example of a conventional lighting device, FIG. 2 is an exploded perspective view of a lighting device showing an embodiment of the present invention, and FIG. 3 is a view taken in the direction of the arrow in FIG. 4 is a side view showing one of the flash lamps EI=E22 in FIG. 2, FIG. 5 is a circuit diagram showing an example of the configuration of the control circuit 15 in FIG. 2, and FIG. The figure shows a modification of the flash lamp.

Claims (1)

[Claims] In a lighting device that includes a light source that emits light by receiving power from a supply means,
1. A lighting device characterized in that it is a flash lamp that emits light at an I If of approximately 1.4 times or less than the commercial power supply voltage.