WO1997016845A1 - Lampe et lecteur d'images l'utilisant - Google Patents
Lampe et lecteur d'images l'utilisant Download PDFInfo
- Publication number
- WO1997016845A1 WO1997016845A1 PCT/JP1996/003146 JP9603146W WO9716845A1 WO 1997016845 A1 WO1997016845 A1 WO 1997016845A1 JP 9603146 W JP9603146 W JP 9603146W WO 9716845 A1 WO9716845 A1 WO 9716845A1
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- WO
- WIPO (PCT)
- Prior art keywords
- heat storage
- lamp
- gas
- lamp unit
- tube
- Prior art date
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Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/024—Details of scanning heads ; Means for illuminating the original
- H04N1/028—Details of scanning heads ; Means for illuminating the original for picture information pick-up
- H04N1/02815—Means for illuminating the original, not specific to a particular type of pick-up head
- H04N1/02845—Means for illuminating the original, not specific to a particular type of pick-up head using an elongated light source, e.g. tubular lamp, LED array
- H04N1/0287—Means for illuminating the original, not specific to a particular type of pick-up head using an elongated light source, e.g. tubular lamp, LED array using a tubular lamp or a combination of such lamps
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J61/00—Gas-discharge or vapour-discharge lamps
- H01J61/02—Details
- H01J61/52—Cooling arrangements; Heating arrangements; Means for circulating gas or vapour within the discharge space
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J61/00—Gas-discharge or vapour-discharge lamps
- H01J61/70—Lamps with low-pressure unconstricted discharge having a cold pressure < 400 Torr
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J65/00—Lamps without any electrode inside the vessel; Lamps with at least one main electrode outside the vessel
- H01J65/04—Lamps in which a gas filling is excited to luminesce by an external electromagnetic field or by external corpuscular radiation, e.g. for indicating plasma display panels
- H01J65/042—Lamps in which a gas filling is excited to luminesce by an external electromagnetic field or by external corpuscular radiation, e.g. for indicating plasma display panels by an external electromagnetic field
- H01J65/046—Lamps in which a gas filling is excited to luminesce by an external electromagnetic field or by external corpuscular radiation, e.g. for indicating plasma display panels by an external electromagnetic field the field being produced by using capacitive means around the vessel
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/024—Details of scanning heads ; Means for illuminating the original
- H04N1/028—Details of scanning heads ; Means for illuminating the original for picture information pick-up
- H04N1/02815—Means for illuminating the original, not specific to a particular type of pick-up head
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/024—Details of scanning heads ; Means for illuminating the original
- H04N1/028—Details of scanning heads ; Means for illuminating the original for picture information pick-up
- H04N1/02815—Means for illuminating the original, not specific to a particular type of pick-up head
- H04N1/02885—Means for compensating spatially uneven illumination, e.g. an aperture arrangement
Definitions
- the present invention relates to an image reading apparatus using the Ranpuyuni' preparative and Ranpuyuni' Bok be found suitable for use in an image reading apparatus which is referred to as an image scanner (BACKGROUND
- an image reading apparatus In an image reading apparatus, generally, a cylindrical lamp is arranged in a width direction of a document, and light generated from the lamp is irradiated on the document. Then, the light reflected from the original or transmitted through the original is read by an image sensor such as a CCD image sensor.
- lamps used in image reading devices and other various devices have been known as lamps used in image reading devices and other various devices.
- a so-called double-electrode hot-cathode tube in which a pair of electrodes 52 a and 52 b acting as hot cathodes are disposed at both ends of a gas-filled tube 51 filled with gas. It has been known.
- Reference numeral 53 denotes a fluorescent substance applied to the inner peripheral surface of the gas sealing tube 51.
- a hot cathode is an electrode that generates heat when electricity is supplied and emits thermoelectrons.
- a so-called double-ended electrode cold cathode tube in which a pair of electrodes 54 a and 54 b acting as cold cathodes are disposed at both ends of a gas filled tube 51 is also known.
- a cold cathode is an electrode that emits electrons when a strong electric field is applied.
- a pair of electrodes 55 a and 55 b having a long length are arranged so as to face each other over almost the entire area in the longitudinal direction of the outer peripheral surface of the gas sealing tube 51.
- An external electrode type cathode ray tube is also known.
- the electrodes 55a and 55b are generally configured as cold cathodes, but if they can be configured with hot cathodes, they may be so configured.
- the gas filling tube 51 is filled with a rare gas such as a neon (Ne) gas, a xenon (Xe) gas, or a mercury (Hg) gas depending on the application. .
- the light amount of the entire lamp 56 decreases, and the light amount decreases more at the center in the longitudinal direction than at both ends.
- the change in the amount of light in the X-axis direction with respect to the amount of light of 100% immediately after lighting as a reference (51 is referred to as a light amount fluctuation rate.
- the difference d2 between the maximum light quantity fluctuation rate (usually the center part) and the minimum light quantity fluctuation rate (usually both end parts) of the light quantity distribution line is called a light quantity fluctuation rate difference.
- the three types of lamps listed in FIGS. 16 to 18 include an external electrode type cathode tube (FIG. 18), a double-ended electrode hot cathode tube (FIG. 16), and a double-ended electrode cold cathode tube (FIG. 16).
- FIG. 18 Comparing Fig. 17), with regard to the amount of emitted light, the outer electrode type cathode tube (Fig. 18) is the most common, followed by the double-electrode hot cathode tube (Fig. 16), followed by the double-electrode cold cathode. Tubes (Fig. 17) are the least. In other words, regarding the amount of emitted light,
- the external electrode type cathode ray tube (Fig. 18) has approximately three times the emitted light intensity of the double-ended electrode cold cathode tube (Fig. 17).
- both the light quantity fluctuation rate cS1 and the light quantity fluctuation rate difference 52 are relatively small.
- both the light quantity fluctuation rate (51 and the light quantity fluctuation rate difference (52) are considerably large.
- Both ends of the hot cathode tube (Fig. 16) and both ends of the cold cathode tube (Fig. 17) have the light intensity fluctuation rate (1 and light intensity fluctuation rate difference (5).
- these lamps emit only a small amount of light, they may not be able to obtain clear read images.
- this lamp emits a large amount of light, read clear images.
- this lamp has a large light intensity fluctuation rate (51 and a light intensity fluctuation rate difference 62), so if this lamp is used as a lamp for an image reading device, it will be affected by light intensity fluctuations over time. Deterioration of the characteristics of the read image Specifically, the amount of light fluctuates greatly between the start and end of reading the original, causing a problem that the reproduced image gradually becomes darker, and particularly the center part becomes darker. .
- Japanese Patent Application Laid-Open No. 7-123234 discloses that a heat insulating material 93 is attached to a fluorescent lamp 92 in close contact with the fluorescent lamp 92 so that a fluorescent light is emitted during light emission.
- Image input that keeps the heat generated by the lamp 92 itself to improve the lighting start-up characteristics, and controls the fluorescent lamp 92 to an appropriate light amount by detecting the illuminance with the photo sensor 98.
- An apparatus is disclosed.
- Reference numeral 91 denotes a document reading background plate
- reference numeral 94 denotes a mirror
- reference numeral 95 denotes a slit
- reference numeral 96 denotes a lens
- reference numeral 97 denotes a CCD image sensor
- reference numeral 99 denotes a document to be transferred in the direction of the arrow.
- the prior art described in this publication is aimed at improving the lighting start-up characteristics of the lamp. In various types of lamps, the light amount fluctuation rate (51 and the light amount fluctuation rate difference ( thing Is not disclosed at all. Disclosure of the invention
- An aspect of the present invention is to reduce both the light amount fluctuation rate (1 and light) and the difference in the light rate (52) for various types of lamps. It is an aspect of the present invention to provide an image reading apparatus using the lamp, and an acute point of the present invention is to appropriately control a lamp used in the image reading apparatus.
- the heat storage means is a substance that has the property of removing heat from the lamp and storing the heat inside itself. In other words, it is a substance that can reduce the rate of temperature rise of the lamp immediately after lighting and can prolong the time required to cool the lamp by radiating heat; a substance with a large heat capacity is desirable. .
- “providing the heat storage means (or heat storage member) around the lamp” means that the heat storage means is directly fixed to the outer or inner peripheral surface of the lamp, or when some member is interposed. This includes the case where heat storage means is placed near the lamp.
- a lamp unit includes a lamp having a cylindrical gas-filled tube filled with gas, and a pair of electrodes provided at both ends of the gas-filled tube.
- a lamp having a cylindrical gas-filled tube filled with gas and a pair of electrodes provided at both ends of the gas-filled tube both ends shown in FIGS. 16 and 17). Since the heat storage means is provided around the electrode-type lamp, heat of the lamp tube wall is removed by the heat storage means and the heat is stored inside the heat storage means.
- both the light quantity fluctuation rate (51 and the light quantity fluctuation rate difference (52) become smaller.
- the light quantity fluctuation rate increases as the lamp tube temperature rises.
- the rate of change in light quantity is also suppressed, and according to this lamp unit, the heat storage means is provided around the lamp. Since the silicone rubber and the metal member provided in contact with the outer peripheral surface of the silicone rubber are provided, the following operational effects can be further obtained: the silicone rubber has thermal conductivity and adhesion.
- the surface is active and all substances can be impregnated
- the metal members have excellent heat storage properties, so the heat of the lamp can be satisfactorily passed through the silicone rubber.
- the heat of the lamp is also stored in the silicone rubber, since the silicone rubber itself also has heat storage properties, so that the rate of temperature rise of the lamp after lighting is effective. And the light quantity fluctuation rate (51 and the light quantity fluctuation rate difference 2) can be satisfactorily reduced.
- the metal member can also serve as a protective member for the lamp.
- a lamp unit includes a lamp having a cylindrical gas-filled tube filled with gas, a pair of electrodes provided at both ends of the gas-filled tube, and a heat storage provided around the lamp.
- the lamp unit according to the present invention includes a cylindrical gas sealing tube filled with a gas, and a pair of electrodes provided on the outer peripheral surface of the gas sealing tube and extending in the longitudinal direction of the gas sealing tube in a state of facing each other. And a heat storage means provided in contact with the outer peripheral surface of the cladding tube.
- an electrically insulating cover surrounding the lamp is provided. Since the heat storage means is provided in contact with the outer peripheral surface of the cladding tube, the heat storage means can be appropriately provided without short-circuiting the electrodes. Moreover, the space between the lamp and the cladding also plays a role as a heat storage means.
- a lamp having a cylindrical gas sealing tube enclosing the gas sealing tube, a pair of electrodes provided on the outer peripheral surface of the gas sealing tube and extending in the longitudinal direction of the gas sealing tube in a state of facing each other; In a position where the lamp does not come into contact, the heat storage means is provided in contact with the outer peripheral surface of the lamp, and an electrically insulating cladding tube surrounding the lamp and the heat storage means.
- the lamp unit of the present invention includes a cylindrical gas filling tube filled with gas, and a pair of electrodes provided on the outer peripheral surface of the gas filling tube and extending in the longitudinal direction of the gas filling tube in a state of facing each other. And an electrically insulating heat storage member provided around the lamp. According to this lamp unit, since the heat storage member having the electrical insulation is provided around the lamp, the heat storage means can be provided without short-circuiting the electrodes. Therefore, with respect to the outer electrode type lamp, both the light quantity variation rate (51 and the light quantity variation rate difference (52) can be satisfactorily reduced. Further, the lamp unit of the present invention has a cylindrical shape filled with gas.
- a lamp having a gas-filled tube, a pair of electrodes provided on the outer peripheral surface of the gas-filled tube and extending in the longitudinal direction of the gas-filled tube in a state of facing each other, and an electrically insulating coating surrounding the lamp.
- a heat storage member made of silicone rubber as a heat storage member provided in contact with the outer peripheral surface of the cladding tube;
- a heat storage metal plate having a c-shaped cross section as a heat storage member.
- the lamp unit and the heat storage metal plate are attached to the cladding tube by a fastening belt, so that a lamp unit can be easily manufactured. In other words, it can be made simply by applying the heat storage sheet and the heat storage metal plate to the cladding tube and tightening it with the fastening belt. Moreover, since the heat storage metal plate has a C-shaped cross section, the heat storage sheet and the heat storage metal plate can be easily applied to the cladding tube, and the fastening belt can be easily tightened.
- An image reading apparatus is an image reading apparatus including: a light source that generates light for irradiating a document; and an image sensor that receives a light image from the document and outputs the signal as an electric signal. Any of the lamp units described in
- It consists of one lamp unit. According to this image reading device, the light quantity fluctuation rate (1 and the light quantity fluctuation rate difference (52) of the lamp are reduced, and a good read image can be obtained.
- the lamp is turned off after the light irradiation for reading the original is completed.
- the lamp is turned off after the light irradiation for reading the original is completed.Thus, by suppressing the temperature rise of the lamp, the heat storage means or the heat storage member can be prevented from being saturated with heat. As a result, it is possible to reliably reduce the lamp light intensity fluctuation rate ⁇ 51 and the light intensity fluctuation rate difference ⁇ 2, and obtain a good read image.
- FIG. 1 is a front sectional view showing one embodiment of a lamp unit and an image reading apparatus according to the present invention.
- FIG. 2 is a perspective view showing the entire lamp unit shown in FIG.
- FIG. 3 is a perspective view showing the lamp unit shown in FIG. 1 cut along a radial direction.
- FIG. 4 is a sectional view of the lamp unit shown in FIG.
- FIG. 5 is a block diagram showing a specific example of an image processing circuit of the image reading device shown in FIG.
- FIG. 6 is a sectional view showing a second embodiment of the lamp unit according to the present invention.
- FIG. 7 is a sectional view showing a third embodiment of the lamp unit according to the present invention.
- FIG. 8 is a perspective view showing a fourth protruding embodiment of the lamp unit according to the present invention and a partially enlarged view thereof.
- FIG. 9 is an exploded perspective view of the same.
- FIG. 10 is a sectional view of the same.
- FIG. 11 is a graph showing light emission characteristics of a lamp using mercury (H g) gas and a lamp using xenon (X e) gas.
- FIG. 12 is a three-dimensional graph showing a temporal change of the light amount fluctuation rate and the light amount fluctuation rate difference of the light source.
- FIG. 13 is a graph showing temporal changes in the tube wall temperature of the lamp provided with the heat storage member and the lamp not provided with the heat storage member.
- FIG. 14 is a graph showing the temporal change of the light intensity fluctuation rate of each of the lamp provided with the heat storage member and the lamp not provided with the heat storage member.
- FIG. 15 is a graph showing an experimental result on the lamp unit according to the present invention.
- C FIG. 16 is a front sectional view showing a hot-cathode tube of a double-end electrode type.
- FIG. 17 is a front sectional view showing a cold-cathode tube of a double-ended electrode type.
- FIG. 18 is a front sectional view showing an external electrode type cold cathode tube.
- FIG. 19 is an explanatory diagram of the prior art.
- FIG. 20 is an explanatory diagram of the related art. BEST MODE FOR CARRYING OUT THE INVENTION
- FIG. 1 is a diagram showing an embodiment of a main part of an image reading device when the lamp unit according to the present invention is used as a light source of the image reading device.
- a carriage 9 is provided below the platen glass 8 on which the original 7 is placed. You.
- the carriage 9 is driven by a transfer device 11 such as a wire or a belt, and reciprocates parallel to the platen glass 8 as indicated by arrows C and C ′.
- the horizontal direction of the drawing is the longitudinal direction of the original, and the direction perpendicular to the paper surface is the width direction of the original.
- the lamp unit 6 extends in the width direction of the document 7, and the width of the effective light emitting portion is set to be wider than the width of the document 7.
- 15 is an image signal generated by extracting the output of a plurality of linearly arranged photoelectric detection elements, for example, photodiodes, as time-series signals using a CCD (Charge Coupled Device).
- CCD Charge Coupled Device
- the photoelectric detection elements are arranged in the width direction of the document 7, that is, in the direction perpendicular to the paper surface of FIG.
- the lamp unit 6 includes, for example, a cylindrical gas sealing tube 1 in which xenon gas Xe is sealed, and a pair of electrodes fixed to the outer peripheral surface of the gas sealing tube 1 by bonding or the like.
- An outer electrode type lamp 3 having 2a and 2b, a cladding tube 4 surrounding the lamp 3, and a heat storage means 20 provided in contact with the outer peripheral surface of the cladding tube 4 are provided. ing.
- the gas sealing tube 1 is formed of, for example, a transparent glass tube, and the inner surface thereof is coated with, for example, a fluorescent substance 1a that emits white light.
- the electrodes 2a and 2b are formed, for example, by sticking an aluminum tape over substantially the entire area in the longitudinal direction of the outer peripheral surface of the gas sealing tube 1, as shown in FIG.
- a high voltage for example, about 3 KV is applied between these electrodes 2a and 2b.
- the cladding tube 4 is made of a synthetic resin having electrical insulation and is formed in a cylindrical shape.
- the space S between the covered pipe 4 and the gas filling pipe 1 is filled with silicone oil as an electrical insulating fluid. The silicone oil may be applied only to the entire surface of the lamp 3.
- the lamp unit 6 emits light over the entire region in the longitudinal direction in the irradiation range H at a predetermined angle, and in the present embodiment, emits white light to the outside.
- the lamp unit 6 is installed in the carriage 9 such that the irradiation range (that is, the light emitting portion) H of the lamp unit 6 faces the document 7 in FIG.
- the heat storage means 20 includes a silicone rubber 17 provided in contact with the outer peripheral surface of the cladding tube 4 and a metal member 18 provided in contact with the outer peripheral surface of the silicone rubber 17. However, it is provided on a portion of the outer peripheral surface of the cladding tube 4 other than the angle range of the light emitting portion H.
- the cross-sectional shape of the silicone rubber 17 also serving as a heat storage member is a semicircular shape, and its length is set to be substantially the same as the length of the cladding tube 4 of the lamp unit 6 as shown in FIG.
- the metal member 18 is made of a heat storage steel plate 18 and is fitted on the outer peripheral surface of the silicone rubber 17.
- the cross-sectional shape of the heat storage steel plate 18 is also semicircular, and its length is set to be substantially the same as that of the silicone rubber 17 as shown in FIG.
- the heat storage steel sheet 18 is a steel sheet mainly composed of iron, for example, a zinc plating steel sheet, which has a large heat capacity and accumulates heat, that is, has excellent heat storage properties.
- Silicone rubber 17 is a very flexible substance, and its surface is active and has the property of penetrating any substance. Therefore, the silicone rubber 17 uniformly and uniformly contacts both the outer peripheral surface of the cladding tube 4 and the inner peripheral surface of the heat storage steel plate 18 without using a special adhesive. In other words, the heat storage steel plate 18 is in close contact with the outer peripheral surface of the cladding tube 4 via the silicone rubber 17.
- an output signal of the CCD image sensor 15 is sent to an image processing circuit 19.
- the image processing circuit 19 includes a CDS (Correlated double sampling) circuit 21 for reducing noise components included in the RGB color output signals from the CCD image sensor 15, and an RGB color signal. And a multiplexer 22 for selecting and outputting one of the two.
- a / D converter 23 for converting an analog signal to be converted into a digital signal.
- the image processing circuit 19 includes a CPU (Central Processing Unit) 24, and a system bus extending from the CPU 24 includes an image correction circuit 25, a color correction circuit 26, and an enlargement. Each circuit of the reduction circuit 27, the binarization circuit 28, and the light source control circuit 29 is connected.
- a DRAM (Dynamic Random Access Memory) and an SRAM (Static Random Access Memory) attached to each circuit are used as a temporary memory, a work file, and the like when performing predetermined processing in each circuit.
- the ROM (Read Only Memory) 31 stores a program that defines the processing order of the image reading device.
- the image correction circuit 25 performs a shading correction process and a gamma correction process.
- shading correction is a correction for making the light amount distribution in the longitudinal direction of the lamp uniform. Specifically, the initial longitudinal light amount distribution of the lamp is stored, and the image signal output from the A / D converter 23 is corrected according to each position in the longitudinal direction. I do. Further, in this image correction circuit 25, by turning off the lamp and sampling the CCD output in the dark, it is possible to eliminate the non-uniformity of the CCD output in the dark.
- Gamma correction is, as is well known, to correct the inherent gamma characteristic of image reading devices, that is, the characteristic that the output gradation value becomes non-linear with respect to the input gradation value. This is the correction that is made in Specifically, the tone value of the image signal output from the A / D converter 23 is corrected by multiplying the tone value by an appropriate coefficient.
- the color correction circuit 26 appropriately corrects the RGB color data so that the RGB color data output from the image reading device matches the output characteristics of the device connected to the subsequent stage.
- the enlargement / reduction circuit 27 enlarges or reduces the size of the image read from the original 7 as desired in the evening.
- the binarization circuit 28 outputs, for example, an image data of 256 tone values output from the A / D converter 23 based on a well-known error diffusion method or another well-known binarization method. Evening is converted to image data with two gradation values of 0 N / 0 FF so as to match the output characteristics of the equipment at the subsequent stage.
- image data of two gradation values created as described above is transformed into a command system for the SCSI interface, and then sent to the host computer or the image output unit of the printer at the subsequent stage.
- image data In addition to the above, various signals sent to the host computer or printer are transformed into a command system for bidirectional parallel interface, and then sent to the operation control unit of the host host or printer at the subsequent stage. .
- the light source control circuit 29 performs various controls on the light source, that is, the lamp 3.
- the power supply to the electrodes 2a and 2b of the lamp 3 is turned ON / OFF, and the light intensity from the lamp 3 is set in the sub-scanning direction (that is, the moving direction indicated by the arrow C of the carriage 9 in FIG. 1). Is controlled so as to be uniform.
- the control of the light intensity in the sub-scanning direction is performed, for example, by controlling the light intensity at each position when the lamp 3 moves in the sub-scanning direction with an optical sensor provided at an appropriate position on the platen glass 8 (or an optical sensor 6 described later). 6)
- Sampling is performed by adjusting the amplification factor of the amplification circuit for the CCD image sensor 15 based on the sampling result, or by controlling the fjt: power supply to the lamp 3 be able to.
- the electrodes 2a and the ramunit 6 in FIG. 3 and FIG. A voltage is applied to 2b, and electrons are emitted from each electrode based on the field emission.
- an AC voltage is applied to each of the electrodes 2a and 2b, so that each electrode alternately acts as a cathode and emits electrons, but one of them is turned off by using a DC power supply.
- the principle of light generation in the lamp 3 can be always used as a cathode.
- the entire surface of the document 7 is read by the CCD image sensor 15.
- the reading process for one original 7 usually takes about three minutes.
- the read image data is subjected to shading correction processing, gamma correction processing, color correction processing, scaling processing and binarization processing by an image processing circuit 19 shown in FIG. Sent to etc.
- both the light quantity fluctuation rate 51 and the light quantity fluctuation rate difference (52) can be reduced favorably.
- 5 1 and the light intensity fluctuation rate difference both 5 and 2 become smaller, so that the entire area from the beginning to the end of reading of the original 7 can be read with a uniform amount of light, and the density of the image reproduced after reading is reduced. It becomes uniform, and an image faithful to the image of the original 7 can be reproduced.
- the heat storage means 20 includes a silicone rubber 17 provided in contact with the outer peripheral surface of the cladding tube 4 and a heat storage steel plate 18 provided in contact with the outer peripheral surface of the silicone rubber. Therefore, the heat of the lamp 3 is transmitted to the heat storage steel plate 18 via the cladding tube 4 and through the silicone rubber 17 in a good (efficient) manner, where the heat is stored. Moreover, the space S between the lamp 3 and the cladding tube 4 and the silicone rubber 17 itself are also present. The heat of the lamp 3 is also stored in the space S and the silicone rubber 17 because it has a sufficient heat storage property. Therefore, the temperature rise rate of the lamp 3 after lighting can be reduced more effectively, and the light quantity fluctuation rate c51 and the light quantity fluctuation rate difference d2 can be made extremely small.
- FIG. 12 is a three-dimensional graph showing the change over time in the light intensity fluctuation rate and the light intensity fluctuation rate difference of the light source.
- the light intensity fluctuation is plotted on the X-axis as described above. The rate is taken, the time is taken on the Y-axis, and the axis of the ramp (56), ie the main scanning direction, is taken on the Z-axis.
- Figure 13 shows two types of external electrode type lamps, one with a heat storage means (or heat storage member) and the same lamp without a heat storage means (or heat storage member).
- FIG. 6 is a graph showing a state of a change in a tube wall temperature of each lamp when lighting for 3 minutes and turning off for a predetermined time are repeated.
- the lighting time is set to 3 minutes because, when one image is read by the image reading device, the lighting time is usually about 3 minutes as described above.
- Figure 14 shows the rate of change of light intensity (curve F) three minutes after the lamp was turned on when a heat storage means (or heat storage member) was provided on the external electrode type lamp, and the heat storage means (or heat storage member) was used for the same lamp.
- It is a graph showing the light intensity fluctuation rate (curve E) three minutes after the lamp was turned on when no lamp was provided.
- the silicone rubber 17 and the heat storage steel plate 18 are fitted around the cladding tube 4 and brought into surface contact, so that the heat generated in the gas filled tube 1 is The heat is efficiently transmitted to the silicone rubber 17 and the heat storage steel plate 18, and the heat is stored therein.
- the time required for reading, for example, the gas filling tube 1 within 3 minutes As the maximum temperature of the wall temperature decreases, the minimum temperature increases.
- the distribution changes so that both the light intensity fluctuation rate (51 and the light intensity fluctuation rate difference (52) decrease as shown from ⁇ 1 to ⁇ 2 in Fig. 12.
- the light intensity fluctuation rate 61 and the light intensity fluctuation rate If both the difference (5 and 2) becomes smaller, the entire area from the start to the end of reading of the original 7 can be read with a uniform amount of light, and the density of the image reproduced after reading becomes uniform It is possible to reproduce an image faithful to the image of 7.
- the heat storage means 20 constituted by the silicone rubber 17 and the heat storage steel plate 18,
- one of the causes of the light quantity fluctuation is a rise in the temperature of the lamp tube wall. Therefore, it is effective to turn off the lamp after reading the document. By turning off the lamp in this way, the following effects can be obtained.
- the heat storage means (or heat storage member) can avoid heat saturation
- FIG. 6 is a sectional view showing a second embodiment of the lamp unit according to the present invention.
- the lamp unit 36 uses a heat storage steel plate 38 as a heat storage means.
- the heat storage steel plate 38 is not provided on the outer peripheral surface of the cladding tube 4 and does not contact the pair of electrodes 2 a and 2 b. At the position, it is adhered to the outer peripheral surface of the gas filling tube 1.
- the heat storage steel plate 38 may be bonded directly to the gas filling tube 1 or bonded through silicone rubber. May be. In the first embodiment shown in FIG.
- a gas filled tube 1 is covered with a cladding tube 4 to form a light emitting tube, and thereafter, a silicone rubber 17 as a heat storage means and a heat storage steel plate 18 are used to emit light.
- the tube was fitted on the outer surface.
- a lamp unit containing the heat storage steel plate 38 is completed.
- FIG. 7 is a sectional view showing a third embodiment of the lamp unit according to the present invention.
- the lamp unit 46 uses a heat storage steel plate 38 as a heat storage means, and the heat storage steel plate 38 is fixed to the outer peripheral surface of the cladding tube 4. Then, the outer circumference of the fixed heat storage steel plate 38 is further surrounded by an outer pipe 41, so that the heat storage steel plate 38 is securely held.
- the outer tube 41 is made of a transparent synthetic resin or glass. According to such a lamp unit 46, the space S1 between the cladding tube 4 and the sheath ⁇ 41 and the sheath tube 41 itself also function as heat storage means. Note that, instead of the heating steel sheet 38, silicone rubber or a laminate of a heat storage steel sheet and silicone rubber may be used. (Fourth embodiment)
- FIG. 8 is a perspective view showing a fourth embodiment of a lamp unit according to the present invention and a partially enlarged view thereof
- FIG. 9 is an exploded perspective view
- FIG. 10 is a sectional view.
- reference numeral 60 denotes a luminous body, and a lamp 3 or a lamp 3 surrounded by a cladding tube 4 can be used.
- Reference numerals 61 and 62 denote holders, which hold both ends of the luminous body 60 (that is, the lamp 3 and the like).
- Reference numeral 63 denotes a heat storage sheet made of silicone rubber as a heat storage member, which is provided in contact with the outer peripheral surface of the light emitting body 60.
- the heat storage sheet 63 is previously formed in a C-shaped cross section in order to improve the attachment property and adhesion to the light emitting body 60.
- Reference numeral 64 denotes a heat storage metal plate having a C-shaped cross section as a heat storage member, which is provided in contact with the outer peripheral surface of the heat storage sheet 63.
- the heat storage metal plate 64 can be made of the same material as the heat storage steel plate 18 described above.
- the heat storage sheet 63 and the heat storage metal plate 64 have substantially the same length as the luminous body 60, more precisely, the length of the exposed portion of the luminous body 60 held by the holders 61 and 62. Is also slightly shorter (about 1-3 mm shorter) ing. Further, the heat storage sheet 63 and the heat storage metal plate 64 are provided with holes 63c and 64c for measuring the amount of light.
- Reference numerals 65 and 65 denote fastening belts made of synthetic resin, and the heat storage sheet 63 and the heat storage metal plate 64 are attached to the luminous body 60 by the fastening belts 65 and 65. .
- cutout portions 64 a and 64 a are partially formed at a portion where the fastening belt 65 is wound.
- a protruding positioning portion 62b for determining the mounting position of the heat storage sheet 63 and the heat storage metal plate 64 is physically provided.
- At one end of the heat storage sheet 63 and the heat storage metal plate 64 there are formed positioning recesses 63b, 64b which are fitted with the positioning portions 62b. .
- the pair of holders 61 and 62 are provided with positioning pins 61a and 62a for mounting the lamp unit in the light shielding plate 12 of the image reading apparatus shown in FIG. Have been.
- the heat storage sheet 63 and the heat storage metal plate 64 are arranged such that the concave portions 63b, 64b are fitted with the positioning portions 62b of the holder 62, and the light-emitting body 6 is formed.
- the heat storage sheet 63 and the heat storage metal plate 64 are formed in a C-shaped cross section, the heat storage sheet 63 and the heat storage metal plate 64 can be easily applied to the luminous body 60 and the fastening work of the fastening belt 65 can be easily performed.
- the irradiation range H of the light emitter 60 is defined by the side edges 63 d and 63 d of the heat storage sheet 63.
- the irradiation range H is defined by the heat storage sheet 63.
- the lamps constituting the light emitter 60 are fluorescent lamps
- the application range of the phosphor is necessarily strictly controlled. There is no need to do so, and costs can be reduced.
- the phosphor may be applied so as to obtain an irradiation range slightly larger than the irradiation range H originally intended (in a narrow coating range).
- the irradiation range H can be defined without applying a phosphor, so that the cost can be further reduced. This effect can also be obtained by a configuration in which the irradiation range is regulated by the heat storage metal plate 64.
- the optical sensor 66 (Fig. ) Can be placed close to the lamp, so that accurate light quantity measurement can be performed.
- the holder 62 Since the holder 62 is provided with a positioning portion 62b for determining the mounting position of the heat storage sheet 63 and the heat storage metal plate 64, the heat storage sheet 63 and the heat storage metal plate 64 are mounted. It can be easily mounted at an appropriate position, and at the same time, the irradiation range H and the positions of the holes 63c and 64c can be easily defined.
- Fig. 18 Although the amount of emitted light is much larger in Fig. 18 (Fig. 18) than in a double-ended electrode hot-cathode tube (Fig. 16) and a double-ended electrode cold cathode tube (Fig. 17), the light intensity fluctuation over time is large. Therefore, if heat storage means is provided for this external electrode type cathode ray tube (Fig. 18), the light quantity variation rate (51 The most significant effect can be obtained by reducing the variation in the rate of variation (52 to make the amount of exposure to the original uniform when reading the original.
- the double-sided electrode hot cathode tube (Fig. 16) or the double-sided electrode Heat storage means can also be provided for the cold cathode fluorescent lamp (Fig. 17).
- the emission color is not limited to a specific color.
- the heat storage means shown in FIGS. 3 and 4 is composed of the silicone rubber 17 and the metal steel plate 18 for heat storage, but may be composed of only the silicone rubber 17 or the metal steel plate 18 for heat storage.
- the heat storage means 20 is provided on the outer peripheral surface of the cladding tube 4, but may be provided on the outer peripheral surface of the lamp 3 without providing the cladding tube 4. This is because silicone rubber has electrical insulation.
- the heat storage means may be provided partially in the longitudinal direction of the lamp.
- the heat storage means may be a substance having a large heat capacity, for example, a steel sheet containing iron as a main component, other general metal materials, non-metal materials such as rubber, or resin. It can be constituted by a sex member or the like.
- an appropriate rubber member can be used instead. Even with such a configuration, (a) the rubber member itself can exhibit a heat storage effect, and (b) electrical insulation between the metal member as the heat storage means and the electrode or between the electrodes can be ensured. c) The adhesion between the lamp and the metal member can be improved.
- the heat storage sheet 63 shown in FIG. 9 was previously formed in a C-shaped cross section, but since the silicone rubber sheet has sufficient flexibility, it is necessarily formed in a C-shaped cross section. No need.
- the lamp unit shown in FIG. 9 includes the pair of holders 61 and 62, a configuration including only one of the holders 62 may be employed.
- the gas sealed in the lamp is not limited to a specific gas. However, when used as a lamp for an image reading device, it is desirable to use a rare gas such as xenon gas or neon gas, which has a property that the amount of light changes little even when the environmental temperature changes.
- the external electrode type lamp 3 shown in Figs. 3 and 4 was supplied. As shown in FIGS. 3 and 4, silicone rubber 17 and a steel plate 18 for heat were mounted on this lamp to form a lamp unit. However, in this experiment, alumina was mixed into the silicone rubber 17. The lamp unit of Sample A was turned on, and the light amount variation rate at each position in the length direction of the lamp unit (ie, the main scanning direction) was measured three minutes after the lighting. After that, the silicone rubber 17 and the heat storage steel plate 18 were removed from the lamp unit of Sample A to make only the lamp, and this was used as Sample B. The lamp of Sample B was turned on, and three minutes after the light was turned on, the light quantity fluctuation rates at the same positions as above were measured. In consideration of the manufacturing variations of the lamp itself, another lamp was prepared and the same experiment as above was performed. The average of two samples A and the average of two samples B were used as experimental results.
- the horizontal axis indicates the position in the length direction of the lamp unit (that is, the main scanning direction).
- the broken line P indicates the central part of the lamp unit in the longitudinal direction.
- the vertical axis of this graph indicates the light intensity fluctuation rate three minutes after lighting, and indicates that the light intensity fluctuation rate increases from the top to the bottom.
- the curve of B shows the light amount fluctuation rate of the lamp (sample B) in the L state without the heat storage means, ie, silicone rubber and the steel plate for heat storage, and A (with heat storage).
- the line indicates the light intensity fluctuation rate of the lamp unit (Sample A) with the heat storage means attached to the same lamp.
- the rate of change in the amount of light is about half when the heat storage means is provided, as compared with the case where it is not provided.
- the fluctuation rate of the light amount in the lamp length direction that is, the main scanning direction
- the fluctuation rate of the light amount in the lamp length direction that is, the main scanning direction
- This feature is a very preferable characteristic when electrically correcting the light quantity fluctuation of the lamp. More specifically, by monitoring the white reference set in the sub-scanning direction, the shading correction is also performed in the sub-scanning direction, and the shading correction is used to electrically correct the light intensity fluctuation of the lamp in the sub-scanning direction. If you are trying to do so, use the "heat storage means"
- both the temporal variation in light quantity after the lamp is turned on and the difference in the variation in light quantity can be significantly reduced.
- the image reading apparatus using the lamp unit the fluctuation of the light amount from the start of reading the original to the end of reading is greatly reduced, and the image of the original can be faithfully reproduced over the entire length direction. .
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- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Electromagnetism (AREA)
- Plasma & Fusion (AREA)
- Facsimile Scanning Arrangements (AREA)
- Light Sources And Details Of Projection-Printing Devices (AREA)
- Vessels And Coating Films For Discharge Lamps (AREA)
Description
Claims
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP96935468A EP0803899B1 (en) | 1995-10-30 | 1996-10-28 | Lamp unit and image reader using the same |
US08/860,684 US6222647B1 (en) | 1995-10-30 | 1996-10-28 | Lamp unit and image reading apparatus using the same |
DE69626001T DE69626001T2 (de) | 1995-10-30 | 1996-10-28 | Leuchte und diese benutzender bildleser |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP7/281697 | 1995-10-30 | ||
JP28169795 | 1995-10-30 | ||
JP22308196A JP3803432B2 (ja) | 1995-10-30 | 1996-08-06 | ランプユニット及びこれを用いた画像読み取り装置 |
JP8/223081 | 1996-08-06 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1997016845A1 true WO1997016845A1 (fr) | 1997-05-09 |
Family
ID=26525263
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP1996/003146 WO1997016845A1 (fr) | 1995-10-30 | 1996-10-28 | Lampe et lecteur d'images l'utilisant |
Country Status (6)
Country | Link |
---|---|
US (1) | US6222647B1 (ja) |
EP (2) | EP0989588B1 (ja) |
JP (1) | JP3803432B2 (ja) |
DE (2) | DE69629851T2 (ja) |
TW (1) | TW385058U (ja) |
WO (1) | WO1997016845A1 (ja) |
Families Citing this family (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH1141394A (ja) * | 1997-07-15 | 1999-02-12 | Canon Inc | 凹凸情報読み取り装置及び画像読み取り装置 |
JPH11346293A (ja) * | 1998-06-01 | 1999-12-14 | Nec Corp | 光源固定部品及び原稿読取装置 |
DE19926556A1 (de) * | 1999-06-11 | 2000-12-14 | Mannesmann Vdo Ag | Beheizbare Entladungslampe |
DE10048409A1 (de) * | 2000-09-29 | 2002-04-11 | Patent Treuhand Ges Fuer Elektrische Gluehlampen Mbh | Entladungslampe mit kapazitiver Feldmodulation |
JP2004537831A (ja) * | 2001-08-02 | 2004-12-16 | コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ | 低圧ガス放電ランプ |
JP3705593B2 (ja) * | 2002-05-27 | 2005-10-12 | Necアクセステクニカ株式会社 | 画像読取装置 |
US20040095620A1 (en) * | 2002-11-19 | 2004-05-20 | Fang Lin | Flat bed scanner |
US6872909B2 (en) * | 2003-04-16 | 2005-03-29 | Applied Science And Technology, Inc. | Toroidal low-field reactive gas and plasma source having a dielectric vacuum vessel |
US8384405B2 (en) * | 2011-04-20 | 2013-02-26 | Tdk Corporation | Method for performing burn-in test |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
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JPS62195847A (ja) * | 1986-02-24 | 1987-08-28 | Matsushita Electric Ind Co Ltd | 照明装置 |
JPS6421960U (ja) * | 1987-07-30 | 1989-02-03 | ||
JPH06118517A (ja) * | 1992-10-06 | 1994-04-28 | Canon Inc | 原稿照明装置 |
JPH07123213A (ja) * | 1993-10-21 | 1995-05-12 | Ricoh Co Ltd | 照光ランプ |
JPH07123214A (ja) * | 1993-10-22 | 1995-05-12 | Hitachi Ltd | イメージスキャナ |
Family Cites Families (10)
Publication number | Priority date | Publication date | Assignee | Title |
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US3668456A (en) * | 1970-08-28 | 1972-06-06 | Sylvania Electric Prod | Lamp having improved press seal |
GB1399260A (en) * | 1972-12-21 | 1975-07-02 | English Electric Valve Co Ltd | Magnetrons |
SU817802A1 (ru) * | 1978-10-02 | 1981-03-30 | Предприятие П/Я М-5907 | Металлогалогенна лампа |
JPS55165564A (en) * | 1979-06-11 | 1980-12-24 | Toshiba Corp | Metallic vapor discharge lamp |
JPS612254A (ja) * | 1984-06-13 | 1986-01-08 | Toshiba Corp | けい光ランプ装置 |
JPS6421960A (en) | 1987-07-16 | 1989-01-25 | Nec Corp | Static induction transistor |
JPS6427157A (en) * | 1987-07-23 | 1989-01-30 | Toshiba Corp | Fluorescent lamp |
US5258857A (en) * | 1988-05-16 | 1993-11-02 | Seiko Epson Corporation | Image input device and method for reading a picture image |
DE4230814A1 (de) * | 1992-09-15 | 1994-03-17 | Patent Treuhand Ges Fuer Elektrische Gluehlampen Mbh | Hochdruckentladungslampe |
US5710485A (en) * | 1995-11-13 | 1998-01-20 | Osram Sylvania Inc. | Neon lamp assembly with RF noise shield |
-
1996
- 1996-08-06 JP JP22308196A patent/JP3803432B2/ja not_active Expired - Fee Related
- 1996-10-28 DE DE69629851T patent/DE69629851T2/de not_active Expired - Lifetime
- 1996-10-28 EP EP99204253A patent/EP0989588B1/en not_active Expired - Lifetime
- 1996-10-28 EP EP96935468A patent/EP0803899B1/en not_active Expired - Lifetime
- 1996-10-28 WO PCT/JP1996/003146 patent/WO1997016845A1/ja active IP Right Grant
- 1996-10-28 US US08/860,684 patent/US6222647B1/en not_active Expired - Lifetime
- 1996-10-28 DE DE69626001T patent/DE69626001T2/de not_active Expired - Lifetime
- 1996-11-05 TW TW085216927U patent/TW385058U/zh not_active IP Right Cessation
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS62195847A (ja) * | 1986-02-24 | 1987-08-28 | Matsushita Electric Ind Co Ltd | 照明装置 |
JPS6421960U (ja) * | 1987-07-30 | 1989-02-03 | ||
JPH06118517A (ja) * | 1992-10-06 | 1994-04-28 | Canon Inc | 原稿照明装置 |
JPH07123213A (ja) * | 1993-10-21 | 1995-05-12 | Ricoh Co Ltd | 照光ランプ |
JPH07123214A (ja) * | 1993-10-22 | 1995-05-12 | Hitachi Ltd | イメージスキャナ |
Non-Patent Citations (1)
Title |
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See also references of EP0803899A4 * |
Also Published As
Publication number | Publication date |
---|---|
US6222647B1 (en) | 2001-04-24 |
DE69626001D1 (de) | 2003-03-06 |
JPH09185954A (ja) | 1997-07-15 |
DE69629851D1 (de) | 2003-10-09 |
DE69626001T2 (de) | 2004-01-08 |
TW385058U (en) | 2000-03-11 |
EP0989588A1 (en) | 2000-03-29 |
DE69629851T2 (de) | 2004-07-15 |
JP3803432B2 (ja) | 2006-08-02 |
EP0803899A4 (en) | 1998-08-19 |
EP0989588B1 (en) | 2003-09-03 |
EP0803899B1 (en) | 2003-01-29 |
EP0803899A1 (en) | 1997-10-29 |
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