受験番号：22IPE002

問１
What is claimed is:1.

An optical sensor comprising:a light-emitting section for emitting a pulsed light to the outside based on apulse signal;a light-receiving section for generating an optical current corresponding to theintensity of an incident light from the outside;a current-voltage converter circuit for converting the optical current into avoltage signal;a high-pass filter for extracting an alternating current component of apredetermined frequency or higher from the voltage signal, the alternating current
component being outputted as a filter output having a signal waveform with a reference
voltage at the center;a polarity inversion amplifier that switches between a noninverting amplifier
state and an inverting amplifier state based on the pulsed signal, the polarity inversion
amplifier outputting the filter output without being inverted in the noninverting
amplifier state and outputting the filter output being inverted around the reference
voltage in the inverting amplifier state; andan integrator for integrating the output of the polarity inversion amplifier
based on the reference voltage.
2.

An optical sensor according to claim 1, wherein the optical sensor further

comprises a delay circuit for delaying the pulsed signal, the pulsed signal being
outputted to the polarity inversion amplifier.
問２
There is known a game system that generates images seen from given
viewpoints within an object space that is a virtual three-dimensional space. This typeof game system is popular as they allow users to experience the so-called virtual reality.
For example, in role-playing games, the player operates a character (object) to cause itto move on a map within the object space. The player enjoys the game by causing thecharacter to fight with enemy characters, converse with other characters, or visit
various towns.
In this type of game system, objects that represent characters and the like areusually made up of a plurality of polygons. Objects made up of polygons are arranged
within an object space. The so-called geometric processing is carried out to generate
images seen from virtual cameras. In this way, game images can be generated that do
not contradict one another even when objects are seen from various directions using
virtual cameras.
While being mathematically correct images, however, game images generated
in this way do not appeal to the sentiments of players.

For example, whenrepresenting characters that appear in animations or cartoons by objects, shading
objects by Gouraud shading or the like provides realistic images, but it generates
images that look different from those that viewers have accustomed to throughanimations, cartoons, and the like.
問３
As shown in Fig. 4, when a human presence sensor 25, installed on the outdoor
side of an entrance door together with a luminaire 20, senses a human body 30, first anillumination lamp of the luminaire 20 switches on. When the illumination lamp of theluminaire 20 switches on, the current that passed through the luminaire 20 is detectedby a current detector circuit 14 (Fig. 3).
With a current detection signal outputted from this current detector circuit 14
serving as trigger, a control unit 200 switches on an illumination lamp of a luminaire 10
after predetermined switch-on interval time has elapsed since the illumination lamp of
the luminaire 20 switched on based on previously-set setting condition information. In
this way, this illumination system 100 can be used to help in the prevention of crimes
and the like because it can make believe that there are residents indoors in the cases
the human body 30 is a suspicious character or the like.
In response to the current detection signal from the current detector circuit 14,
a controller 15 for example controls an LED circuit 17 to switch on an LED to inform theswitch-on status of the illumination lamp of the luminaire 20, and turns a switch 19 into
an ON state after previously-set switch-on interval time t1 has elapsed since theillumination lamp of the luminaire 20 switched on. When the switch 19 is in the ON
state, current passes in the electric lamp line on the side of the luminaire 10, and theillumination lamp of a luminaire 10 switches on to be in the switch-on state.