Can I get a sprite from a sprite sheet?

Hello, I made SpriteSheet by using TexturePacker.

34493-save.png

And I try to use Sprite in the SpriteSheet. But, Sprite Value is Null.

using UnityEngine;
using System.Collections;

public class TileMap : MonoBehaviour {
    public GameObject tile;
	void Start () {
        (GameObject.Instantiate(tile) as GameObject).GetComponent<SpriteRenderer>().sprite = Resources.Load<Sprite>("character");
	}
	void Update () {
	
	}
}

How Can I get a sprite from Sheet in the script?

sorry to unskilled in English…