JPH0418286Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a document illumination device such as a facsimile machine.

[Prior art and its problems]

Many image readers, such as those used in facsimile machines, use sensors such as CCDs to read information such as characters and graphics written on documents, which are illuminated by a light source from a document illumination device. Here, the light source has a light ripple (fluctuation in the amount of light)
It is required that the light intensity is small, that the rise is quick, and that the light distribution characteristics become stable immediately. If the light ripple from the light source is large, the image sensor will misread it and transmit incorrect information. For example, if you use an incandescent light bulb that is lit by a stabilized power source by controlling the phase of the commercial frequency as this light source, it will take half a cycle of the commercial frequency (10 msec at 50 Hz and 8.3 msec at 60 Hz).
Of this, there is a non-lighting time of 1 to 2 msec, so
The optical ripple is large, which is not desirable. Therefore, fluorescent lamps driven by high frequency power sources are often used. When a fluorescent lamp is lit at high frequency, the optical ripple becomes extremely small, but on the other hand,
Fluorescent lamps have the disadvantage that they start up slowly and require time to stabilize their light distribution characteristics. In particular, in small facsimile machines, the fluorescent lamps are small and
Since the power consumption is low, the temperature rise is slow and requires a certain amount of warming up.

For this reason, a heating resistance wire is disposed along the axis on the outer surface of the compact fluorescent lamp other than the aperture (light emitting portion), and electricity is applied to this wire to keep the compact fluorescent lamp warm. Heating with a resistance wire requires a temperature sensor to control the heating temperature and a temperature fuse that blows out when it overheats. Conventionally, a temperature sensor and a temperature fuse were attached directly to a compact fluorescent lamp with a heating resistance wire in contact with the resistance wire, and a light source that integrated these components was placed in a document illumination device. For this reason, even though the compact fluorescent lamp is normal, if the temperature sensor or temperature fuse malfunctions,
Small fluorescent lamps also had to be replaced, and conversely, when a small fluorescent lamp's lifespan ended, the temperature sensor and temperature fuse also had to be disposed of. Further, the unit of such a document illumination device moves forward during reading,
Many of them move backwards and return at high speed, but in this case, a large acceleration is applied to the light source, but since compact fluorescent lamps with integrated temperature sensors and temperature fuses are heavy, the force acting on them when moving is large. Therefore, it was necessary to make the structure for attaching the small fluorescent lamp to the unit strong.

[Purpose of invention]

Therefore, the present invention has small optical ripple, good start-up stability, easy wiring for compact fluorescent lamps, simple installation structure, and easy installation of temperature sensors, temperature fuses, or compact fluorescent lamps. The object of the present invention is to provide a document illumination device that can be replaced with the original illumination device.

[Structure of the device and its function]

The document illumination device of the present invention has a unit stand, a small fluorescent lamp that has an aperture, is held by a holder on the unit stand, and is arranged along the axis on the outer surface of the small fluorescent lamp other than the aperture. A heating resistance wire, an aluminum reflective film covering the resistance wire, a temperature sensor and a temperature fuse connected in series with the resistance wire and placed in contact with the outer surface of the compact fluorescent lamp, and a temperature sensor and a temperature fuse placed on the unit stand. , a printed circuit board that holds a temperature sensor and a temperature fuse.

In other words, since the compact fluorescent lamp is kept warm by a resistance wire, the light ripple is small and the start-up stability is good. Since it is not directly attached to the lamp, it is easy to replace just the compact fluorescent lamp or just the temperature sensor and temperature fuse. Furthermore, since the weight of the temperature sensor and temperature fuse is not added to the compact fluorescent lamp, the force acting on the compact fluorescent lamp when the unit is moved is small, and the mounting structure to the unit is simple. Furthermore, since a printed circuit board is used, wiring of the compact fluorescent lamp is easy and the structure is compact.

[Example] The present invention will be specifically described below based on an example shown in the drawings.

The drawing shows a facsimile document illumination device. Compact fluorescent lamp 1 has a total length of 200 mm and low power consumption.
Since it is 10W and is lit by a high frequency power supply, the optical ripple is extremely small. For convenience, fluorescent paint 12 is applied to the inner surface of the glass envelope 11 of the small fluorescent lamp 1, as shown by the dotted line, but it is not applied to a predetermined width in the axial direction, and this part is an aperture 13. . A heating resistance wire 2 is arranged on the outer surface of the glass enclosure 11, and an aluminum reflective film 3 covers the heating resistance wire 2 except for the aperture 13. Therefore, light is strongly radiated from this aperture 13. On both sides of the glass enclosure 11 are bases 1 made of silicone resin.
4 is attached to the base 14, and a pair of protrusions 15 are provided on the base 14.

A holder 5 having a notch groove 51 is provided upright on the unit base 4, and by fitting the protrusion 15 into the notch groove 51, the small fluorescent lamp 1 can be attached.
is retained. So that you can understand from now on,
The structure for attaching the compact fluorescent lamp 1 to the unit base 4 is very simple, and it can be easily removed. A printed circuit board 6 having printed wiring on its back surface is disposed on the unit base 4. A temperature sensor 7 and a temperature fuse 8 are held by this printed circuit board 6, and the temperature sensor 7 and temperature fuse 8 are in contact with the aluminum reflective film 3 in the part where the heating resistance wire 2 is buried. are doing. The temperature sensor 7 and the temperature fuse 8 are connected in series with the heating resistance wire 2 by printed wiring, and the temperature sensor 7 performs ON/OFF control according to the temperature of the small fluorescent lamp 1. Keep it warm at around 40℃. If the compact fluorescent lamp 1 overheats, the temperature fuse 8 blows out, stopping the current supply to the heating resistor wire 2, thereby preventing an accident.

Then, the document illumination device built into the facsimile machine with such a configuration is energized, and the start button is pressed.
When turned on, the small fluorescent lamp 1 lights up and the unit stand 4 moves to illuminate the original. At this time,
Since the compact fluorescent lamp 1 is driven by a high-frequency power source, the optical ripple is very small. However, since the compact fluorescent lamp 1 is pre-insulated by the heating resistance wire 2, it can be installed as soon as the start button is turned on. Stable optical characteristics and no need for warming up. When the unit stand 4 returns, a large acceleration is applied to the small fluorescent lamp 1, but since the small fluorescent lamp 1 is lightweight, the structure for mounting it on the unit stand 4 is simple as described above. Also, no problems occur. Further, when the temperature sensor 7 or the temperature fuse 8 breaks down or the life of the small fluorescent lamp 1 ends, it is only necessary to replace each component. And since the printed circuit board 6 is used, wiring is easy.
It can have a compact configuration.

[Effect of idea]

As explained above, the document illumination device of the present invention insulates a small fluorescent lamp with a heating resistance wire, and prints without attaching the temperature sensor and temperature fuse necessary for this heating resistance wire to the small fluorescent lamp. Since it is held by the board and comes into contact with the small fluorescent lamp, the light ripple is small and the start-up stability is good, the wiring of the small fluorescent lamp is easy, and the mounting structure to the unit base is simple. , the document illumination device can be made such that only the temperature sensor, temperature fuse, or small fluorescent lamp can be easily replaced.

[Brief explanation of drawings]

FIG. 1 is a plan view of an embodiment of the present invention, FIG. 2 is a partial front view, and FIG. 3 is a sectional view. DESCRIPTION OF SYMBOLS 1... Compact fluorescent lamp, 11... Aperture, 2... Heating resistance wire, 3... Aluminum reflective film, 4... Unit stand, 5... Holder, 6...
Printed circuit board, 7...Temperature sensor, 8...Temperature fuse.

Claims (1)

[Scope of utility model registration request] A unit base, a small fluorescent lamp having an aperture and held by a holder on the unit base, a heating resistance wire arranged along the axis on the outer surface of the small fluorescent lamp other than the aperture, and the resistance wire. An aluminum reflective film covering the wire, a temperature sensor and a temperature fuse connected in series with the resistance wire and placed in contact with the outer surface of the compact fluorescent lamp, and a temperature sensor and a temperature fuse placed on the unit base. A document illuminating device characterized by comprising a printed circuit board.