JPH07201306A - Stabilized fluorescent lamp and electrophotography duplicating device - Google Patents

Abstract

PURPOSE: To provide a stabilized fluorescent lamp. CONSTITUTION: A lamp 34 includes a long extending tube 52 equipped with a phosphor material layer 54 formed on an inside surface of a reflection coating 56, a large quantity of mercury, and internal rare gas sealed in the tube. An aperture 58 is provided so as to emit an illumination band and to be directed to a platen. Operating power to the lamp is provided by a lamp power supply in response to a lamp-on (scanning mode) signal. A resistive heater blanket 60 is attached to the lamp and the blanket surrounds the tube of the lamp completely. At least, a part 60A of the blanket 60 covering the aperture is substantially transparent relative to emitted light. The blanket 60 is connected to a heater power controller 61. Accordingly, the blanket 60 is supplied with power independently of the lamp 34.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a manuscript (document).
A fluorescent lamp (a fluorescent lamp) with an aperture (aperture, window) of the kind used to provide directional illumination, such as a transparent resistor that completely surrounds the lamp and covers the aperture area of the lamp. A lamp having a heater blanket having a portion.

[0002]

Fluorescent lamps are generally constructed as shielded tubes, the inner surface of which is coated with a phosphor or a reflective layer. Small transparent windows, commonly referred to as lamp apertures, are formed by removing the longitudinal strips of reflector / phosphor coating. The tube is a low pressure mercury vapor, and argon,
It is filled with a common inert filling gas such as krypton, xenon or a mixture of these gases. When an electric field is applied to electrodes attached to the ends of the envelope, mercury atom excitation and subsequent relaxation produces UV radiation that produces:
The phosphor fluoresces, producing visible light emitted through the aperture.

The temporal stability of the axial light output from the lamp aperture, called the lamp illumination profile, depends on a number of variables (variables), the most important of which being the lamp. Is the mercury vapor pressure.
The internal aggregate mercury vapor pressure is controlled by the coldest spot in the lamp called the cold spot. Spatial illumination changes occur in response to local temperature changes as mercury moves back and forth between the cold spot and the inner wall of the lamp envelope.

To obtain temporary stability, a heater sleeve is commonly added to the valve. Conventional fluorescent lamp heater sleeves consist of a heater added to the lamp in such a way that the lamp aperture area is unobstructed, and thus some of the total lamp surface area is not heated. 1A and 1B respectively show a front view and a cutaway view of a prior art lamp 10.
The lamp 10 has a shield tube 12 having a reflective coating 14 applied to the inner surface of the tube 12 and a phosphor coating 16 applied on the coating 14.
A lamp jacket 18 surrounds the tube 12 and covers the coatings 14 and 16. Coating 14, 16
And the jacket 18 is a transparent aperture 2 for the lamp.
It is added to leave 0. When the prior art lamp is in standby mode, the aperture 20 is indirectly heated by conduction from the jacket 18. When hit by the arc, further heating occurs as a result of the heat generated by the discharge. Under certain circumstances, additional warming of the aperture disturbs the thermal profile of the lamp, resulting in mercury migration. This migration of mercury in the mercury distribution causes local changes in radiant power. Furthermore, it should be noted that since the lamp aperture surface is not heated directly, it is possible that the surface of this aperture acts as a cold spot and actually serves to regulate the lamp radiance. When this occurs, the temporary stability of the lamp is adversely affected due to poor control of the cold spot temperature. This problem is partly dealt with by raising the jacket set point, which allows more energy to be conducted to the aperture area, but preferably up to the jacket temperature above the desired cold spot temperature. It is to raise. This approach has limited effectiveness and unnecessarily increases lamp wall temperature. U.S. Pat. Nos. 4,751,551, 4,147,947, and 4,916,352 disclose jacketed fluorescent lamps. The prior art does not disclose a resistive sleeve or jacket that covers the lamp aperture.

[0005]

According to the present invention,
The heater or jacket is added in such a way as to warm the entire circumference of the valve wall while maintaining high permeability through the aperture area. Therefore, a more uniform thermal profile can be obtained. With this approach, the entire bulb wall can be maintained at the same temperature except for the cold spot, thus reducing the potential for local variations in mercury vapor pressure (and corresponding lamp radiance). As a result,
Temporary stability is improved. More particularly, the present invention relates to a stable fluorescent lamp, which comprises electrodes inside the tube for producing visible light through an aperture with electrodes sealed at both ends and when the lamp is powered. A stretched shield tube and a resistive heater blanket attached to the outer surface of the tube, the resistor being light transmissive at least in the area overlying the aperture and further including means for applying power to the heater blanket. And a combination of a sex blanket.

A stabilized fluorescent lamp according to a second aspect of the present invention is the stabilized fluorescent lamp according to the first aspect, wherein the heater blanket has a resistance pattern formed on a transparent substrate.

According to a third aspect of the present invention, there is provided an electrophotographic reproduction apparatus, which comprises at least a linear fluorescent lamp having an aperture for forming an illumination profile of the target surface and the scanning mirror on the target surface original. The heater blanket has at least a transparent transparent portion that covers the aperture when scanned in a copy mode by an optical assembly that includes the heater blanket.

An electrophotographic reproduction apparatus according to claim 4 is the electrophotographic reproduction apparatus according to claim 3, wherein the illumination profile is modified by adding opaque portions to transparent portions in a predetermined pattern. To be done.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 2, an original scanning system is shown in which an original 30 is placed on a fluorescent lamp 3.
Illumination is provided by an illumination assembly 32 including a reflector 4, a scanning mirror and a scanning mirror. This type of assembly is used in the RIS scanning system disclosed in US Pat. No. 5,029,311 the contents of which are incorporated herein by reference. The lamp 34, shown in cross-section in FIG. 3, comprises an elongated tube 52 with a phosphor layer 54 formed on the inner surface of a reflective coating 56, a large amount of mercury and an internal noble gas sealed within the tube. Including. Aperture 58 is provided to emit the illumination band and to direct the illumination band toward the platen. Operating power to the lamp is provided by the lamp power supply 59 in response to the lamp-on (scan mode) signal. A resistive heater blanket 60 is attached to the lamp, with blanket 60 completely surrounding the lamp tube.
At least the segment 60A of blanket 60 that covers the aperture is substantially transparent to the emitted light. The blanket 60 is connected to the heater power controller 61. Therefore, the blanket is powered independently of the lamp. In the preferred embodiment, the blanket 60 shown in the unrolled state of FIG. 4A and in the cutaway view of FIG. 4B includes an opaque resistive pattern 62 disposed on a transparent substrate 64. A transparent pressure sensitive adhesive layer 66 is added to the bottom of the substrate to provide intimate physical contact between the blanket and the lamp tube.
FIG. 5A shows a transparent substrate 64A having two patterns 62.
And FIG. 64B shows a cutaway view of another embodiment sandwiched between 64B and 64B. The transparent adhesive layer 66A includes the substrate 64A and the pattern 62.
A transparent adhesive layer 6 which provides a contact between
6B provides a contact between the base 64B and the lamp tube. In yet another embodiment, shown in cross-section in FIG. 5B, the pattern 62 is etched into the substrate 64.

Example Blanket 60 was designed for a lamp operating at 20 watts and 0.4 amps. The resistance pattern 62 is
In the case of this embodiment, the positive temperature coefficient of nickel-iron (PT
C; made from positive temperature coefficient (C) material. Since the resistance of the PTC material increases with temperature, the device itself acts as a temperature sensor without the need for a separate thermistor or thermostat. Base 6
4 is a single layer of 18 mm thick Mylar ^TM (Mylar (trade name)). Blanket is 1 at 24 Volts
Operates at a temperature set point of 75 ° F (79.4 ° C). The set point resistance is about 125 ohms. The blanket is maintained at the temperature setpoint by the precision controller 61. Illumination of uniform thermal profile is emitted from aperture 58. Although the lamp aperture radiance is somewhat reduced, the reduction can be minimized by selecting the width and spacing of the pattern 62 within the aperture area, ie the subregion coverage of the pattern 62.

While the embodiments disclosed herein are preferred, it will be apparent from this teaching that various other changes, variations, or modifications can be made by those skilled in the art. For example, although in the preferred embodiment, the blanket is shown attached to the envelope by a pressure sensitive adhesive, the blanket may also be shrink-wrapped onto the lamp using a transparent shrink-wrap sleeve. The entire blanket does not have to be transparent. That is, the aperture segment is the only part that needs to be light transmissive. However, from a manufacturing point of view, it may be easier to make the entire blanket transparent. As a further modification, the lighting profile may be modified by screen-printing a dot pattern on the aperture portion of the blanket or by adding resistive segments to the aperture areas that are not connected to power. The profile range can be determined by the size or spacing of the preselected dots.

[0012]

The present invention provides a lamp having a heater blanket that completely surrounds the lamp and has a transparent resistive portion that covers the aperture area of the lamp.

[Brief description of drawings]

FIG. 1A is a front view of a conventional aperture fluorescent lamp, and FIG. 1B is a sectional view thereof.

FIG. 2 illustrates an original scanning system incorporating the stable fluorescent lamp of the present invention.

3 shows a sectional view of the lamp of FIG.

4A is a plan view of a preferred embodiment of the heater blanket of the present invention (inside) in the unrolled configuration, and FIG. 4B is a cross-sectional view thereof.

5A and 5B are cross-sectional views of a heater blanket of another embodiment.

[Explanation of symbols]

 34 Lamp 54 Phosphor 56 Reflective Coating 58 Aperture 60 Blanket 61 Heater Power Controller

Claims (4)

[Claims] 1. A stabilized fluorescent lamp comprising electrodes sealed at both ends and including means inside the tube for producing visible light through an aperture when the lamp is powered. An elongated shield tube and a resistive heater blanket attached to the outer surface of the tube, the resistive heater blanket being light transmissive at least in the region overlying the aperture and further including means for applying power to the heater blanket. Fluorescent lamp with a combination of a transparent blanket. 2. The stabilized fluorescent lamp of claim 1, wherein the heater blanket comprises a resistive pattern formed on a transparent substrate. 3. An electrophotographic reproduction apparatus in which a document on a target surface is in copy mode by an optical assembly including at least a linear fluorescent lamp with apertures for forming an illumination profile on the target surface and a scanning mirror. An electrophotographic reproduction apparatus in which the heater blanket, if scanned, has at least a transparent transparent portion covering the aperture. 4. An electrophotographic reproduction apparatus according to claim 3, wherein the illumination profile is modified by adding opaque areas to transparent areas in a predetermined pattern.