Lamp Array Research Articles

A novel illuminator design in a rapid thermal processor

The instantaneous insertion of an opaque shutter between the lamp arrays and the wafer in a rapid thermal processor can significantly increase the ramp-down rate from 90 to 400/spl deg/C/s during the cooling period. This shutter can prevent the residual heating of lamp filament as well as the self-heating from the reflector due to the mirror image of the wafer. To compensate for the weak irradiation intensity close to the edge of the linear lamps, a multiplane reflector design is used to increase the uniformity of irradiation intensity in the direction along the linear lamps. The distance between the reflector plane and the linear lamp is designed to be smaller at the edge, as compared to the center, of the linear lamp. Together with two oblique reflectors at the ends of the linear lamps, a typical three-plane reflector design can increase the uniformity by 60% in a typical lamp configuration.

UV‐B effect on Quercus robur leaf litter decomposition persists over four years

SummaryThe effects of elevated UV‐B (280–315 nm) radiation on the long‐term decomposition of Quercus robur leaf litter were assessed at an outdoor facility in the UK by exposing saplings to elevated UV‐B radiation (corresponding to a 30% increase above the ambient level of erythemally weighted UV‐B, equivalent to that resulting from a c. 18% reduction in ozone column) under arrays of cellulose diacetate‐filtered fluorescent UV‐B lamps that also produced UV‐A radiation (315–400 nm). Saplings were also exposed to elevated UV‐A radiation alone under arrays of polyester‐filtered fluorescent lamps and to ambient solar radiation under arrays of nonenergized lamps. After 8 months of irradiation, abscised leaves were placed into litter bags and allowed to decompose in the litter layer of a mixed deciduous woodland for 4.08 years. The dry weight loss of leaf litter from saplings irradiated with elevated UV‐B and UV‐A radiation during growth was 17% greater than that of leaf litter irradiated with elevated UV‐A radiation alone. Annual fractional weight loss of litter (k), and the estimated time taken for 95% of material to decay (3/k) were respectively increased and decreased by 27% for leaf litter exposed during growth to elevated UV‐B and UV‐A radiation, relative to that exposed to UV‐A alone. The present data corroborate those from a previous study indicating that UV‐B radiation applied during growth accelerates the subsequent decomposition of Q. robur leaf litter in soil, but indicate that this effect persists for over four years after abscission.

Negligible influence of elevated UV-B radiation on leaf litter quality of Quercus robur

We tested whether elevated UV-B radiation applied to Quercus robur, a principal climax species of northern Europe, would influence concentrations of polyphenolics (Folin–Denis tannins and lignin), phenylpropanoid moieties of lignin, carbohydrates (monosaccharides and holocellulose), or nutrient elements (K, Ca, Mg, P and N) in recently-abscised leaf litter. Saplings of Q. robur were exposed for 2 years at an outdoor facility in the UK to a 30% elevation above the ambient amount of erythemally-weighted UV-B (280–315 nm) radiation under arrays of fluorescent lamps with cellulose diacetate filters, which transmitted both UV-B and UV-A (315–400 nm) radiation. Saplings were also exposed to elevated UV-A alone under arrays of lamps with polyester filters and to ambient radiation under non-energised arrays of lamps. We found little evidence that elevated UV-B radiation influenced leaf litter quality. Data pooled for both years indicated an 8% increase in vanillic acid concentration in litter from polyester-filtered lamp arrays, relative to non-energised arrays, and 8% and 6% increases, respectively, in concentrations of acetovanillone in litter from polyester- and cellulose diacetate-filtered lamp arrays, relative to non-energised lamp arrays. Arabinose concentration in litter from cellulose diacetate-filtered lamp arrays was 3% higher than in litter from polyester-filtered arrays, and glucose concentration in litter from cellulose-diacetate filtered lamp arrays was increased by 6%, relative to non-energised arrays. There were no main effects of elevated UV on the concentrations of holocellulose, polyphenolics or nutrient elements. We conclude that exposure to elevated UV-B does not substantially influence the initial chemical composition of Q. robur leaf litter and that any increases in UV-B radiation arising from ozone depletion over northern mid-latitudes will be unlikely to affect nutrient cycling and decomposition in Quercus woodlands through effects on litter quality alone.

UV‐B radiation constrains the photosynthesis of Quercus robur through impacts on the abundance of Microsphaera alphitoides

Summary Quercus robur saplings were exposed at an outdoor facility in the UK to supplemental levels of UV‐B radiation (280–315 nm) under arrays of cellulose diacetate‐filtered fluorescent lamps which also produced UV‐A radiation (315–400 nm). Saplings were also exposed to supplemental UV‐A radiation under arrays of polyester‐filtered lamps and to ambient levels of solar radiation under arrays of unenergized lamps. The UV‐B treatment was modulated to maintain a 30% elevation above the ambient level of erythemally weighted UV‐B radiation. Naturally occurring infections by oak powdery mildew (Microsphaera alphitoides) were more abundant, and developed more rapidly, on lammas leaves of saplings which were exposed to treatment levels of UV‐B radiation than on leaves of saplings exposed to supplemental UV‐A or to ambient levels of solar radiation over 12 weeks in summer and autumn 1996. An analysis of leaf photosynthetic capacities revealed that M. alphitoides infection reduced the quantum efficiency of photosystem (PS) II by 14% at moderate irradiance. Although there was no direct effect of UV‐B radiation on PSII photochemistry, exposure of saplings to supplemental UV‐A radiation under polyester‐filtered lamps resulted in a 17.5% decrease in PSII quantum efficiency, compared with saplings exposed to ambient solar radiation. The results from our study suggest that photosynthesis of Q. robur may be constrained by exposure to UV‐B radiation in the natural environment through impacts on the abundance of M. alphitoides.

Pulsed laser ablation deposition of thin films on large substrates

We have designed and built an ultra-high vacuum chamber which allows thin film deposition on large area (up to 100 mm diameter) flat substrates and on three-dimensional substrates (e.g. 100 mm long, 50 mm diameter cylinders) by the pulsed laser deposition and reactive pulsed laser deposition techniques. Heating of substrates during and after film deposition is possible using either resistive heaters or a lamp array. Metal (Cu) and metal nitride (TiN) and carbide (TiC) films were deposited on Si wafers (60 and 100 mm diameter), three-dimensional steel substrates (steel cylinders and screws), Teflon plates, and paper sheets.

Effects of elevated ultraviolet radiation on Quercus robur and its insect and ectomycorrhizal associates

SummarySaplings of pedunculate oak (Quercus robur L.) were exposed at an outdoor facility to modulated levels of elevated UV‐B radiation (280–315 nm) under treatment arrays of cellulose diacetate‐filtered fluorescent lamps which also produced UV‐A radiation (315–400 nm). Saplings were also exposed to UV‐A radiation alone under control arrays of polyester‐filtered lamps and to ambient levels of solar radiation under arrays of unenergized lamps. The UV‐B treatment corresponded to a 30% elevation above the ambient level of erythemally weighted UV‐B radiation. Sapling growth and the occurrence of associated organisms were examined over two years. In both years, leaves of saplings exposed to UV‐B treatment were thicker and smaller in area relative to leaves exposed to ambient and control levels of radiation. UV‐B treatment also retarded bud burst at one sampling in the first year of the study. Some responses were recorded which were common to both treatment and control arrays, implying that UV‐A radiation, or some other factor associated with energized lamps, was responsible for the observed effects. Saplings under treatment and control arrays were taller in the first year of the study, suffered greater herbivory from chewing insects, and had lower root dry weights and greater insertion heights of secondary branches than saplings exposed to ambient levels of radiation. Exposure of saplings to elevated UV‐A radiation alone under control arrays increased estimated leaf volumes in the second year of the study and reduced the number of secondary branches and the total number of branches per sapling after two years, relative to both treatment and ambient arrays. There were no effects of elevated ultraviolet radiation on shoot or total plant weight, root/shoot ratios, stem diameter, the numbers or insertion heights of primary or tertiary branches, total leaf number, timing of leaf fall or frequency of ectomycorrhizas. Our study suggests that any increases in UV‐B radiation as a result of stratospheric ozone depletion will influence the growth of Q. robur primarily through effects on leaf morphology.

Elevated UV‐B radiation effects on experimental grassland communities

SummaryExperimental grassland communities (turves) were exposed to supplemental levels of UV‐B radiation (280–315 nm) at an outdoor facility, under treatment arrays of cellulose diacetate‐filtered fluorescent lamps which also produce UV‐A radiation (315–400 nm). Control treatments consisted of arrays of polyester‐filtered lamps, which allowed for exposure to UV‐A radiation alone, and arrays of unenergized lamps allowing for exposure to ambient levels of solar radiation.

Elevated UV‐B radiation incident on Quercus robur leaf canopies enhances decomposition of resulting leaf litter in soil

AbstractWe examined whether the exposure of Quercus robur L. to elevated UV‐B radiation (280–315 nm) during growth would influence leaf decomposition rate through effects on litter quality. Saplings were exposed for eight months at an outdoor facility in the UK to a 30% elevation above the ambient level of erythemally weighted UV‐B radiation under UV‐B treatment arrays of fluorescent lamps filtered with cellulose diacetate, which transmitted both UV‐B and UV‐A (315–400 nm) radiation. Saplings were exposed to elevated UV‐A alone under control arrays of lamps filtered with polyester and to ambient radiation under unenergised arrays of lamps. Abscised leaves from saplings were enclosed in 1 mm2 mesh nylon bags, placed in a Quercus–Fraxinus woodland and were sampled at 0.11, 0.53, 1.10 and 1.33 years for dry weight loss, chemical composition and saprotrophic fungal colonization.At abscission, litters from UV‐A control arrays had ≈ 7.5% higher lignin/nitrogen ratios than those from UV‐B treatment and ambient arrays (P < 0.06). Dry weight loss of leaves treated with elevated UV‐B radiation during growth was 2.5% and 5% greater than that of leaves from UV‐A control arrays at 0.53 and 1.33 years, respectively. Litter samples from UV‐B treatment arrays lost more nitrogen and phosphorus than samples from ambient arrays and more carbon than samples from UV‐A control arrays. The annual fractional weight loss of litter from UV‐B treatment arrays was 8% and 6% greater than that of litter from UV‐A control and ambient arrays, respectively. Regression analyses indicated that the increased decomposition rate of UV‐B treated litters was associated with enhanced colonization of leaves by basidiomycete fungi, the most active members of the soil fungal community, and that the frequency of these fungi was negatively associated with the initial lignin/nitrogen ratio of leaves.

A test of the effect of supplemental UV‐B radiation on the common frog, Rana temporaria L., during embryonic development

AbstractThe release of certain man‐made chemicals has led to recurrent, seasonal destruction of ozone in the upper atmosphere, allowing more solar radiation in the UV‐B waveband to reach the Earth. Consequently, many amphibians may suffer increased exposure to UV‐B at various stages in their lives. Embryonic stages of species which spawn in the spring, in shallow, open water, are at high risk of increased exposure. We exposed newly fertilized eggs of one such species, Rana temporaria L., to sunlight with and without supplemental UV‐B. We used outdoor arrays of lamps to simulate the increase in UV‐B which might result from previously documented ozone depletion. From immediately after fertilization to when hatchlings began feeding, ambient solar UV‐B, weighted for DNA‐damaging potential, was supplemented by ≈ 81% in 1995 and 113% in 1996. These levels of supplementation approximated the increase in solar UV‐B expected to result from losses of 21% and 25%, respectively, of the total amount of ozone in the atmospheric column, relative to pre‐ozone‐depletion values. We found no evidence that these additions of UV‐B radiation increased the incidence of mortality or overt developmental abnormality among embryos. We stress the need for appropriate dosimetry in studies of effects of UV‐B on organisms.

Flashlamp instruments for measuring the Midcourse Space Experiment satellite contamination environment

The xenon flashlamp (XF) and krypton lamp and radiometer (KLR) are two of a suite of instruments that monitor the particulate and gaseous contamination environments of the Midcourse Space Experiment spacecraft. The near-field particulate measurement comprises the high-intensity XF that illuminates a volume of space in the field of view of a wide field-of-view visible imager. Radiation scattered by illuminated contaminant particles is imaged. The intensity of the radiation is related to a particle’s size and composition. The particle’s track yields information about its velocity and trajectory. From ground calibration data we estimate a sensitivity to detect particles smaller than 1 μm and to determine cross-field velocities from 1 mm s−1 to 50 m s−1. We present early mission particulate data from known particle-generating events and from comparatively quiescent times. These results are consistent with previous measurements. The KLR measures the local H2O density in a volume of space approximately 0.5 m from one corner of the spacecraft. The instrument comprises an array of krypton vacuum ultraviolet line source lamps that dissociate H2O and a near-UV radiometer that detects the chemiluminescence from the OH dissociation products. Ground calibrations indicate that the instrument has sufficient sensitivity to detect H2O densities as low as 1.5×107 molecules cm−3. H2O is the primary outgassed species during the early part of a spaceflight, and is a particular concern to cryogenic sensors, such as the Spatial Infrared Imaging Telescope III (SPIRIT III) on this spacecraft. Early mission results are in overall agreement with prelaunch predictions.

Direct Effects of Elevated UV-B Radiation on the Decomposition of Quercus robur Leaf Litter

Decomposing Quercus robur L. leaf litter was exposed for 64 weeks at an outdoor facility to supplemental levels of UV-B radiation (280-315 nm) under treatment arrays of cellulose diacetate-filtered fluorescent lamps which also produce UV-A radiation (315-400 nm). Litter was also exposed to UV-A radiation alone under control arrays of polyester-filtered lamps and to ambient levels of solar radiation under arrays of unenergised lamps. The treatment corresponded to a 30% elevation above the ambient erythemally-weighted level of UV-B radiation. Litter was sampled after 11, 39 and 64 weeks and was examined for differences in mass loss, decomposition constants (k), chemical composition and the abundances of saprotrophic fungi. No effects of UV radiation on k values were recorded, but after 11 weeks, percentage mass loss of litter exposed to UV-B radiation under treatment arrays was 3% lower than under control arrays and 2% lower than under ambient arrays. After 39 weeks, litters exposed to UV-A radiation under control arrays had 10% lower total nitrogen contents and 13% higher C:N ratios than those litters exposed beneath ambient arrays. At the last sampling, litters exposed to supplemental UV-B radiation had 5% higher carbon contents than those under ambient arrays. A 2.4-fold increase in the frequency of lamina particles of litter that were uncolonised by fungi was recorded in litter exposed to UV-B radiation under treatment arrays, compared to ambient arrays. The abundances of the saprotrophic fungi Cladosporium spp. and Acremonium persicinum (Nicot) W. Gams were decreased by 50% and 91%, respectively, under UV-B treatment arrays compared to ambient arrays, and the abundance of coelomycete conidiomata recorded on leaves was increased by 12% under treatment arrays, compared to ambient. Dactylella spp. were not recorded on litter exposed to UV-A radiation under control arrays and UV-A radiation applied under control and treatment arrays apparently increased the abundance of Polyscytalum fecundissimum Riess. on litter. UV radiation had fewer effects on the abundances of decomposer fungi that develop in leaf tissues than it did on those that develop on leaf litter surfaces. We conclude that increased fluxes of UV-B radiation as a result of stratospheric ozone depletion will have subtle but wide-ranging impacts on the decomposition of litters in oak woodlands.

Ultraviolet‐B radiation influences the abundance and distribution of phylloplane fungi on pedunculate oak (Quercus rohur)

SUMMARYThe effects of u. v.‐B radiation (280–315 nm) on the fungi occurring on the lammas leaves of pedunculate oak (Quercus robur L.) were examined using saplings that were exposed at an outdoor facility to supplemental levels of u. v.‐B radiation under treatment arrays of cellulose diacetate‐filtered fluorescent lamps, which also produce u. v.‐A radiation (315–400 nm). Saplings were also exposed to u. v.‐A radiation alone under control arrays of polyester‐filtered lamps, and to ambient levels of solar radiation under arrays of unenergized lamps. The u. v.‐B treatment corresponded to a 30 % elevation above the ambient level of erythemally‐weighted u. v.‐B radiation. The fungi were examined weekly over a 4–month‐period in summer and autumn 1995 using two techniques, the spore fall and leaf impression methods, which differentiated between those fungi occurring on the upper (adaxial) and lower (abaxial) surfaces of the leaves. The abundances of Aureobasidium pullulans (De Bary) Arnaud and Sporobolomyces roseus Kluy. et van Niel, two leaf yeasts which had adaxial: abaxial ratios of < 1 under ambient levels of u. v.‐B radiation, were negatively correlated with increasing ambient levels of u. v.‐B radiation and were significantly reduced on adaxial leaf surfaces by supplemental levels of u. v.‐B. There were few effects of supplemental u. v.‐B radiation on the abundances of these yeasts on abaxial leaf surfaces. The abundances of the dematiaceous hyphomycetes, Cladosporium spp. and Epicoccum nigrum Link., species with adaxial: abaxial ratios of ≥ 1 under ambient levels of u. v.‐B radiation, were not correlated with ambient levels of u. v.‐B radiation, nor were they usually affected on either leaf surface by supplemental u. v.‐B radiation. Alternaria spp. and Microdochium nivale (Fr.) Samuels & Hallet showed consistent responses on adaxial leaf surfaces to u. v.‐A radiation applied under control and treatment arrays. Our results suggest that current levels of shortwave radiation already influence the distribution of fungi on leaf surfaces and that future increases in u. v.‐B radiation will directly affect the abundances of specific phylloplane fungi.

Silicon Rapid Thermal Processing with Ripple Pyrometry

ABSTRACTThermal processing in silicon integrated circuit fabrication steps for dopant activation, metal silicides, annealing, and oxidation commonly uses single-wafer furnaces that rapidly heat wafers with incandescent infrared lamps. Radiation pyrometers and thermocouple probes are the principle methods of measuring wafer temperature for closed-loop control of rapid thermal processes. The challenge with thermocouples is in dealing with heat from the lamps and non-ideal thermally resistive wafer contact. The challenge with pyrometry is in compensating for the variable emissivity of wafer surfaces and suppressing interference from the lamps. Typical deposited or grown layers of silicon nitride, silicon dioxide, and polycrystalline silicon can produce dramatic changes in emissivity. Layer thicknesses and composition are generally not known with sufficient accuracy, so a method for real time in situ emissivity compensation is required. Accufiber introduced a “ripple technique” to address this issue. The idea is to use two probes, separately sensing radiation from the wafer and the lamps, and extracting AC and quasi-DC parts from each. The AC signals provide a measure of the reflectivity of the wafer, and thence emissivity, as well as the fraction of reflected lamp radiation present in the DC signals. Lucent Technologies introduced a method of using AC lamp ripple to measure wafer temperatures with two radiation probes at a wall in the furnace. One probe views radiation emanating from the wafer through a gap in the lamp array. The other probe has a wide field of view to include lamp radiation. The accuracy of Lucent devices, determined from process results on wafers with various emissivities, is typically in the range of 12°C to 18°C at three standard deviations.

SiON large area deposition with a deep-UV flash argon/krypton lamp array

Silicon oxynitride, SiO x N y ( x, y ∼), grown by flash deep-ultraviolet chemical vapor deposition (FUV CVD) has attractive optical, electrical, mechanical and chemical properties which make it a suitable dielectric with low dielectric constant for both microelectronics and photonics applications. At low temperatures (300–400°C) large area nearby-stoichiometric films are deposited. At different precursor flow ratios, SiO x N y films are obtained with variable x and y. This allows variation of optical functions with x and y. FUV CVD films are low in hydrogen and free of water and hydroxyl. Since the deposition temperature is significantly lower than that observed in other conventional techniques, they are essentially free of stress.

Appropriate controls in outdoor UV‐B supplementation experiments

Abstract Quercus robur L. saplings were exposed in an outdoor experiment to supplemental levels of UV‐8 (280–315 nm) radiation using treatment arrays of cellulose diacetate‐filtered fluorescent lamps that also produce UV‐A (315–400 nm) radiation. Saplings were also exposed to UV‐A radiation alone using control arrays of the same lamps filtered with polyester and to ambient levels of radiation, using arrays of unenergized lamps. The UV‐B treatment was modulated to maintain a 30% elevation above the ambient level of UV‐B radiation, measured by a broad‐band sensor weighted with an erythemal action spectrum. Saplings exposed to UV‐B radiation beneath treatment arrays developed thicker leaves than those beneath ambient and control arrays. Despite the fact that supplemental levels of UV‐A radiation were only a small percentage of ambient levels, apparent UV‐A effects were also recorded. Significant increases in sapling height, lammas shoot length and herbivory by chewing insects were observed under treatment and control arrays, relative to ambient, but there were no differences between the responses of saplings under treatment and control. These data imply that supplemental UV‐A radiation or other effects associated with energised lamps can significantly affect plant growth parameters and herbivory in outdoor studies. We conclude that the results from current outdoor UV‐B supplementation experiments that lack control exposures using polyester‐filtered lamps need to be interpreted with caution and that future supplementation experiments should include appropriate controls.

Tunable UV-flash krypton lamp array useful for large area deposition and in situ UV annealing of Si-based dielectrics

A low pressure VUV flashlamp at 100 Torr has been developed as a tool for ‘cold’ UV CVD and processing. The current density is related in a tunable fashion to the VUV spectral distribution (160–260 nm) up to 20 Hz. A high brightness (3400 W/Hz cm 2 sr) Kr flashtube was shown to be a superior VUV source to Xe and Ar for Si-based dielectrics. The VUV efficiency of the Kr flashlamp, operated at up to 10 kA/cm 2, is relatively high, up to 10%, in the spectral region. By setting four efficient Kr flashtubes, in a separate cavity, a lamp source, together with the UV CVD system characteristics, are shown useful to overall ‘cold’ processing, with focus on uniform large area, cleaning, and in situ deposition, up to 3% for 3″. The deposition rates are conveniently high, ∼100 Å/min at 350°C, but well controllable to obtain several dielectric thin films on III–V materials: silicon dioxide, nitridised silicon dioxide, and silicon nitride. Device quality electrical and optical features for III–V technology are demonstrated: a zero-hysteresis MIS-InP and as a proof of the passivation of GaAs surface, the MIS-GaAs capacitor.

An Analytic Approach to the Radiation Fields of Tubular Halogen Lamp Arrangements in RTP Reactor Blocks

AbstractStarting with basic physical radiation principles and with Beers law formulas for the radiation characteristics of arrays of pointlike radiation sources and tubular halogen lamps are analytically derived. Different arrangements of tubular halogen lamps are considered and compared with each other. Homogeneity criteria are worked out and it is demonstrated that the minimum homogeneity distance between a plane in which all filaments are arranged parallel to each other, and an object depends only on the distance between two neighbouring filaments and thus can be given by a simple number. Interesting aspects for RTP equipment manufacturers as well as for users are demonstrated by comparing different lamp arrangements with each other: In crossed lamp fields latticelike inhomogeneity knots arise in the object plane at points where the lamp filaments of the upper and the lower lamp plane cross. If the filaments are arranged parallel to each other in two filament planes, very homogeneous results are obtained when the filaments of the two planes interlace.

An Analytic Approach to the Radiation Fields of Tubular Halogen Lamp Arrangements in RTP Reactor Blocks

ABSTRACTStarting with basic physical radiation principles and with Beers law formulas for the radiation characteristics of arrays of pointlike radiation sources and tubular halogen lamps are analytically derived. Different arrangements of tubular halogen lamps are considered and compared with each other. Homogeneity criteria are worked out and it is demonstrated that the minimum homogeneity distance between a plane in which all filaments are arranged parallel to each other, and an object depends only on the distance between two neighbouring filaments and thus can be given by a simple number. Interesting aspects for RTP equipment manufacturers as well as for users are demonstrated by comparing different lamp arrangements with each other: In crossed lamp fields latticelike inhomogeneity knots arise in the object plane at points where the lamp filaments of the upper and the lower lamp plane cross. If the filaments are arranged parallel to each other in two filament planes, very homogeneous results are obtained when the filaments of the two planes interlace.

Turning Control of an Autonomous Vehicle Using Fluorescent Lamp Arrays on the Ceiling

An autonomous navigation method based on TV vision system on board a vehicle is under investigation. Our method is to use fluorescent lamp arrays on the ceiling as a lighthouse to control the vehicle. The object of this paper is to propose a method which controls the vehicle to turn at 90 degrees and to show the vehicle motion on the specified course in a virtual factory. This paper consists of three parts :(1) First, the basic principle of turning the vehicle is explained. Next, experiments are carried out to examine this turning method using the practical vehicle. Furthermore, a method to specify the turning direction is suggested.(2) In the next section, the vehicle motion in the perpendicular direction to fluorescent lamps on the ceiling is outlined.(3) In the last section, the vehicle motion on the specified course in the factory is shown by using computer simulation.

Orientation Control of an Autonomous Vehicle by Means of Angular Information from Fluorescent Lamps

This paper mainly describes an orientation control scheme of a vision-based autonomous vehicle by means of fluorescent lamps on the ceiling. The long shape of a fluorescent lamp makes this control possible. First, we propose the method that discriminates a fluorescent lamp from the other light sources and gives the distance and the angle between the vehicle and the fluorescent lamp. Then, the errors of the detected distance and angle are estimated and it is found that they are small enough to control the vehicle. Lastly, experimental results of the vehicle navigation are shown. The vehicle can move along the fluorescent lamp array or in a certain direction from the fluorescent lamp array. These two types of vehicle motion give the autonomous vehicle more flexibility to decide the vehicle's path in factories.