受験番号：22IPE003

問１）
Claim 1
A photosensor comprising:a light-emitting section that emits pulsed light toward outside based on a pulsesignal;a light-receiving section that generates a photocurrent corresponding to an
intensity of light entered from outside;a current-voltage converting circuit that converts the photocurrent into avoltage signal;a high-pass filter that extracts from the voltage signal an alternating-current
component

havingapredeterminedfrequencyorhigher,andoutputs

thealternating-current component as a filter output exhibiting a signal waveform whose
center is a reference voltage;a polarity inverting amplifier that is switched between a noninverting
amplifier state and an inverting amplifier state according to the pulse signal, thepolarity inverting amplifier not inverting the filter output so as to output the filter
output in the noninverting amplifier state, and the polarity inverting amplifier
inverting the filter output with respect to the reference voltage so as to output the filter
output in the inverting amplifier state; andan integrator that integrates outputs from the polarity inverting amplifier
based on the reference voltage.
Claim 2The photosensor according to claim 1, further comprising:a delay circuit that delays the pulse signal and outputs the delayed pulse signal
to the polarity inverting amplifier.

問２）
There have been known game systems for generating an image viewed from agiven view point in an object space, which is a virtual three-dimensional space. Suchgame systems allow a user to experience so-called virtual reality, and thus are very
popular. For example, in a role-playing game, a player operates a character (object) so
as to move the character on a map in an object space. The player enjoys the game, forexample, by making the character battle against an opponent character, by making thecharacter talk with another character, or by making the character visit various towns.
In a game system as above, an object representing a character or the like istypically constituted by a plurality of polygons. The object constituted by the polygons is
positioned in an object space. So-called geometry processing is performed thereon, sothat an image viewed from a virtual camera is generated. This makes it possible togenerate a game image without any inconsistency even when the object is viewed fromvarious directions by the virtual camera.
However, the game image generated in this manner involves a problem offailing to arouse sympathy of the player so much, although such a game image ismathematically correct. For example, in order to represent a character in an animation
work or a cartoon by an object, shading may be given to the object, e.g., by Gouraud
shading. This enables to yield an image which is realistic but has an atmospheredifferent from that familiar to viewers in the animation work or the cartoon.

問３）
As shown in Fig. 4, when a human sensor 25, which is provided on the outsideof an entrance door together with a luminaire 20, detects a human 30, an illuminatinglamp of the luminaire 20 is first lit. When the luminaire 20 is lit, a current that has
flowed through the luminaire 20 is detected by a current detection circuit 14 (Fig. 3).
Triggered by a current detection signal from the current detection circuit 14, acontrol unit 200 lights an illuminating lamp of a luminaire 10 after a predeterminedlighting interval time period has elapsed since the lighting of the illuminating lamp of
the luminaire 20 according to pre-set setting condition information, for example. Thus,
by use of such an illumination system 100, for example, when the human 30 is a
suspicious person, it is possible to make the human 30 think as if a resident is present
inside the room. Accordingly, the illumination system 100 is useful to crime prevention.
According to the current detection signal from the current detection circuit 14,
a control section 15 reports the lighting of the illuminating lamp of the luminaire 20,e.g., by controlling an LED circuit 17 so as to light an LED, and turns on a switching
section 19 after a pre-set lighting interval time period t1 has elapsed since the lightingof the illuminating lamp of the luminaire 20. When the switching section 19 is turned on,a current is flown to a lamp wire of the luminaire 10, so that the luminaire 10 becomes alighting state in which the illuminating lamp of the luminaire 10 is lit.