To investigate the relationship between colorimetric values of a CRT display and colored papers when their color appearances are matched in practical situations, color matching experiments were conducted under “The recommended condition for color matching between self-luminous displays and hard-copies” that has been proposed by the Illuminating Engineering Institute of Japan.
The experiments were performed under five CRT screen conditions: 1) CRT monitor shaded by a small hood, 2) shaded by a large hood, 3) without a hood, 4) without a hood but with a black border on the CRT bezel and 5) shaded by a large hood with a white surrounding. Conditions 1 to 4 are expected to cause different contrast effects, but Condition 5 is not.
The results show that the colorimetric values of a color-matched CRT display and colored papers are not equal in practical situations, and that the disagreement is caused by the contrast effectsbe tween the CRT screen and its surroundings, and also by other effects. The contrast effect can be predicted from the luminance value of the CRT screen surroundings.
These results suggest that the CRT screen surroundings be carefully considered for accurate cross-media color reproduction.

抄録全体を表示

Data of irradiance from the sun and the sky on the building surfaces are absolutely necessary for practical planners and engineers in order to design excellent and comfortable environments of building interiors. The direct solar irradiance is always estimated, but the sky irradiance is almost neglected because of the lack of the knowledge of the sky radiance distribution that is the origin of the sky irradiance.
The sky irradiance can be obtained as the product of the relative sky radiance and the zenith radiance.
An equation which expresses the relative yearly mean sky radiance distribution by the solar altitude to the zenith radiance has been composed based upon the data gained at the IDMP station in Kyushu University in 1994 and 1995 and reported in the preceding paper (part 2). An equation for the yearly mean zenith radiance formulated as the next step is shown in this paper. The equation has been composed as a function of the solar altitude and the frequency of occurrences. The yearly mean irradiance by the solar altitude can be easily calculated by applying the result of this research work, which is surely useful for detailed design of the advanced thermal environments of building interiors.

抄録全体を表示

We compared the concentration levels of subjects under several lighting conditions in which the ratio of the task illuminance to the ambient illuminance was varied.In order to evaluate the subjects' levels of concentration, subjective appraisals and measurements of the subjects' lambda responses (one of the brain's responses) were carried out. The results showed a close correlation between the subjective appraisals and the measured lambda responses.We found that lighting in which the ratio of the ambient illuminance to the task illuminance was from 0.02 to 0.3 provided the optimum conditions for concentration.

抄録全体を表示

We carried out the psychophysical experiment matching and comparing the intensity of a flash light with that of a fixed light, because some papers have reported that the formula for the effective intensity of a flash light presented by Blondel & Rey in 1912 can not be applied when the background is bright and when the luminance exceeds a certain threshold.
As a result of this experiment, we propose that the effective intensity of a flash light when background condition is 0 cd/m² he exuressed by
log_e (Y) = [-4.4+0.88×log_e (X)] +0.7× log_e (T)
Y: Effective intensity of a flash light in lx.(Illuminance of a fixed light at the observer's eye in lx.)
X: Illuminance of a flash light at the observer's eye in lx.
T: Lighting time period in msec.

抄録全体を表示

We calculate and evaluate the influence of the monochromator on the colorimetry of light sources.
A spectroradiometric measurement is recommended to get accurate chromaticity coordinates of light sources in JIS Z 8724. In order to get x and y within 0.001 accuracy, we clarify that wavelength error must be within 0.5nm and intrinsic wavelength resolution must be within 5nm. In addition, we clarify that even when intrinsic wavelength resolution is not negligible, the relation between slit width and sampling interval derived by Watarai⁴⁾ and Nakagawa⁵⁾ , is valid.

抄録全体を表示

It is well known that brightness perception for object colors of the same hue increases with saturation. In this paper we investigate the effect of saturation on illuminant mode perception and brightness perception and compare those two perceptions using two methods: the paired comparison method and the matching method, on a CRT. We used the paired comparison method to investigate the effect of saturation on illuminant mode perception using stimuli of equal luminance and equal brightness perception. The results show that a higher saturation leads to a stronger illuminant mode perception for equal luminance stimuli. They also show that a highly saturated stimulus leads to a strong perception of illuminant mode for equal brightness stimuli, which means that the effect of saturation on illuminant mode perception is more than on brightness perception. The matching method shows that a lower saturation stimulus has higher luminance at equal illuminant mode and at equal brightness. The change of luminance in illuminant mode is greater than that in brightness.
Results from the two methods correspond well; the perception of illuminant mode and brightness increases with increasing saturation, but the saturation effect on the perception of illuminant mode is stronger than on that of brightness.

抄録全体を表示

We analyzed the heat transfer characteristics of a new type of road traffic signal head developed to prevent the phantom illumination. A spherical multi-lenses-unit (lens-unit) is mounted in the traffic signal head. TS OR bulb with band mirror is employed as a signal lamp. The distribution of temperature in radial direction has a peak value at nearby 50mm on both surfaces of the lens-unit. The temperature at the position of 3 mm aparting from the surface of the lens-unit inside the signal lamp has a maximum at nearby 85mm. The distance of 50 or 85mm is measured from the center of the lens-unit. The rising curve of the temperature with time shows good agreements between experiment and calculation on surface side of the lens-unit inside the signal lamp. For a sheet of vertical flat-plate assumed for the lens-unit, a calculation shows that the temperature in axial direction rapidly decreases within the distance of 5 mm from the outside surface of the lens-unit.

抄録全体を表示

The fluorescence spectra of intact leaves illuminated with laser light (Ar⁺laser 488 nm) shows two peaks around 685 nm (Hip) and 740 nm (FIp). The intensity ratio of the FIp peak to the Fllp peak (FIp/FIIp ratio) is linearly elevated with increasing chlorophyll content. In this investigation, in order to examine the effect of temperatures from 5 °C to 60 °C on chlorophyll fluorescence spectra and on the measurement of chlorophyll content, chlorophyll fluorescence spectra of wild type (nourin-8) and chlorina mutant (MGS 88) rice leaves were measured. The spectra were analyzed by resolving them into Gaussian curve components using five tentative fluorescence emitter components (F680, F685, F695, F720 and F740) based on the model proposed by Wittmershaus et al., and one minor emitter component (F780) at a longer wavelength.
The peak ratio and emitter area ratios of laser-induced fluorescence spectra of the nourin 8 leaves indicated constant value within a temperature range from 20 °C to 40 °C. Values changed at low temperatures (below 20 °C) and at high temperatures (above 40 °C). The method of measuring chlorophyll content by using peak ratio and emitter area ratios of LIF spectra was useful in practical application in the optimum temperature range (20 °C to 40 °C) for growing rice. Resolution analysis of fluorescence spectra showed changes in fluorescence spectra induced by temperature and chlorophyll contents were affected by the emitters (F680, F685 and F740) relating to lightharvesting chlorophyll.
We conclude that the LIF method is useful for monitoring the effect of temperature of light-harvesting chlorophyll and the chlorophyll content in rice plant leaves of normal temperature conditions in the plant factory.

抄録全体を表示

The purpose of this study is to clearly define the meaning of affluent lighting in a living room and together with its related elements.
Two psychological experiments, one using the evaluation grid method and the other using the semantic differential method, were carried out using photographs of living rooms.
1) 24 meanings and 41 elements emerged from the results of experiments using the evaluation grid method. Some examples of the elements are the kinds of luminaire, space design, and so on.
2) The meanings of affluent lighting were explained by feelings of comfort, brightness, and variety from the results of experiments using the semantic differential method. The important elements were plural luminaires and brightness. The results show that affluent lighting can suit various situation in a living room.

抄録全体を表示

This paper concerned a low-pass filtering method for evaluating the visibility of shapes. With this method, observers discriminate shapes while their images are filtered in gradually lower spatial frequencies. We estimate the visibility by measuring discrimination thresholds in cut-off frequencies. The method has been validated in practical situations where visual information carried by high spatial frequencies is degraded. Such situations are surprisingly common under unfavor-able conditions, including peripheral vision, mesopic or scotopic vision, isoluminance, image motion, and also in the eyes elderly persons and clinically impaired eyes.
In this experiment, the numerals from 14 font families were estimated by the lowpass filtering method. Eight numeral images, extracted from one of each font family, were rotated clockwise by 0, 90, 180, or 270 degees, and sequentially presented on a CRT display in random order for 200 ms each. The image contrast was about 0.99. Their positions were randomly distributed around the fixation point. The letters were low-pass filtered by a ground glass placed between an observer and the display surface. The cut-off frequency was defined at 1/e of the image peak contrast. The observer was asked to judge whether the target letter, which was presented at the beginning of each session, was included in the stimulus sequence consisting of eight numerals. Threshold cut-off frequency was obtained by a simple staircase method.
Obtained visibility estimates agreed well among observers, and a series of working hypotheses for shapes of more legible letters were suggested.

抄録全体を表示

A discussion of the relationship between helios and luminance showes that helios has the same concept of luminance.
To date helios, the photometric concept is introduced to the photometric system on the basis of a surface light souce by P. Moon, has been misunderstood for a long time.

抄録全体を表示