An improved solution mining method for a soluble target layer such as potash, comprising injecting spent crystallizer brine unsaturated with salt generally horizontally into the top of the target layer to enable immediate target layer dissolution with waste salt accumulating in the sump while the dissolved target material is produced. A response time calculation unit finds response time of the users from the communication information. The pixel sequence of the scanning line to be thickened corresponds a replacement point of the replaced pixel of the first color. A threshold voltage of the second transistor is adjusted by implanting through the second gate while masking the first region.