A smart watch having a strap changing in color according to a user's mood, the smart watch comprising:
- a body configured to collect information on a plurality of measurement targets associated with a user or around the user to write state information, wherein the plurality of measurement targets include a face color divided into red normal, and pale, a pupil shape divided into enlarged and reduced, a pulse divided into fast, normal, and slow, a body temperature divided into high, normal, and low, a voice divided into excited and calm, a ambient light divided into bright, normal), and dark, a ambient temperature divided into high, normal, and low, and an activity divided into fast movement, slow movement, and no movement,
- compare the state information with state combination information that a plurality of pieces of combination information and a displayed color for each of the plurality of pieces of combination information are determined, select one piece of corresponding combination information among the plurality of pieces of combination information included in the state combination information, and
- select a displayed color matching the selected combination information;
- and
- a strap that is connected with the body to fix the body to a user's body part, includes an output means of the displayed color, and outputs the displayed color through the output means according to a control of the body,
- wherein the body includes a sensor unit configured with at least one of a temperature sensor, a pulse sensor, a blood pressure sensor, an accelerator sensor, a GPS sensor, a gyro sensor, and an optical sensor, or an input device including a camera or a microphone, in order to collect the state information,
- wherein the body further includes a control unit, in which the control unit receives a measured value obtained by measuring each of a plurality of measurement targets from the sensor unit or the input unit, divides the measured value into grades for each of the measurement targets, combines the measured values divided into grades for each of the measurement targets, and writes the state information,
- wherein the body further includes a storage unit, in which the storage unit stores a predetermined reference value for each of the measurement targets to be divided into the grades, and the control unit compares the reference value with the measured value to be divided into the grades,
- wherein the combination information is an expected value of the state information that is computable by combining the grades of the respective measured values for each of the plurality of measurement targets,
- wherein the state combination information includes the displayed color matching with the one piece of corresponding combination information, so that based on the state combination information, the control unit is configured to switch to one of positive states among good feelings, excitement, and motivation due to exercise in response to a user's current state being one of negative states among anger, depression, and boredom based on the plurality of measurement targets, and configured to maintain the user's current state in response to the user's current state being the one of positive states based on the plurality of measurement targets,
- wherein the output means is configured to include a light source capable of outputting one or more colors according to the control, a power supply means supplying power to the light source, and a connecting means connecting the light source and the power supply means, and the strap has at least one of the light source, the power supply means, and the connecting means embedded inside or attached to a surface thereof.