diff --git a/hgdriver/hgdev/hg_scanner.cpp b/hgdriver/hgdev/hg_scanner.cpp
index c7b6aa9..cf2d910 100644
--- a/hgdriver/hgdev/hg_scanner.cpp
+++ b/hgdriver/hgdev/hg_scanner.cpp
@@ -3459,9 +3459,22 @@ int hg_scanner::try_third_app_handle_start(bool& handled)
 {
 	int ret = SCANNER_ERR_OK;
 
+	handled = false;
+	return ret;
+
 	handled = !async_io_;
 	if (handled)
 	{
+		if (user_cancel_)
+		{
+			if (status_ != SCANNER_ERR_OK && status_ != SCANNER_ERR_USER_CANCELED)	// call stop after exception occurs, start a new scanning ...
+			{
+				handled = false;
+				VLOG_MINI_1(LOG_LEVEL_DEBUG_INFO, "call start after user cancelled while status is %s, we start a new scanning\n", hg_scanner_err_description(status_));
+
+				return ret;
+			}
+		}
 		while (wait_usb_result_.try_wait())
 			std::this_thread::sleep_for(std::chrono::milliseconds(3));
 
@@ -3505,13 +3518,14 @@ int hg_scanner::try_third_app_handle_start(bool& handled)
 }
 int hg_scanner::try_third_app_after_start(int err)
 {
-	if (!async_io_)
-	{
-		while (wait_img_.is_waiting() && !wait_usb_.is_waiting())
-			std::this_thread::sleep_for(std::chrono::milliseconds(10));
-		if (wait_img_.is_waiting() && wait_usb_.is_waiting())
-			err = status_;
-	}
+	//if (!async_io_)
+	//{
+	//	while (wait_img_.is_waiting() && !wait_usb_.is_waiting())
+	//		std::this_thread::sleep_for(std::chrono::milliseconds(10));
+	//	if (wait_img_.is_waiting() && wait_usb_.is_waiting())
+	//		err = status_;
+	//	
+	//}
 
 	return err;
 }
@@ -3607,9 +3621,9 @@ int hg_scanner::save_usb_data(std::shared_ptr<tiny_buffer> data)
 {
 	int ret = SCANNER_ERR_OK;
 	unsigned int bytes = data->size();
-
+		
 	usb_img_index_++;
-	VLOG_MINI_1(LOG_LEVEL_DEBUG_INFO, "USB read one picture with %u bytes\n", data->size());
+	VLOG_MINI_3(LOG_LEVEL_DEBUG_INFO, "USB packet(%04d) of picture with %u bytes(status: %d)\n", usb_img_index_, data->size(), data->get_image_statu());
 	if (dump_usb_path_.length()) //这两台设备不是jpg的图 所以不能直接处理
 	{
 		char	name[80] = { 0 };
@@ -4081,11 +4095,98 @@ void hg_scanner::on_language_changed(void)
 		}
 	}
 }
+int hg_scanner::wait_one_image_from_start(bool& handled)
+{
+	int		ret = SCANNER_ERR_OK;
+
+	handled = false;
+	if (!async_io_)	// non-callback 
+	{
+		while (is_running() != THREAD_RUNNING_IDLE)
+		{
+			handled = true;
+			if (final_imgs_.size())
+			{
+				break;
+			}
+		}
+
+		if (final_imgs_.size())
+		{
+			IMH	head = { 0 };
+
+			handled = true;
+			if (final_imgs_.front(&head))
+			{
+				if (head.statu & IMG_STATUS_DOUBLE)
+					ret = SCANNER_ERR_DEVICE_DOUBLE_FEEDING;
+				else if (head.statu & IMG_STATUS_JAM)
+					ret = SCANNER_ERR_DEVICE_PAPER_JAMMED;
+				else if (head.statu & IMG_STATUS_STAPLE)
+					ret = SCANNER_ERR_DEVICE_STAPLE_ON;
+				else if (head.statu & IMG_STATUS_SIZE_ERR)
+					ret = SCANNER_ERR_DEVICE_SIZE_CHECK;
+				else if (head.statu & IMG_STATUS_DOGEAR)
+					ret = SCANNER_ERR_DEVICE_DOGEAR;
+			}
+		}
+		else if (handled) // overed normal or exception
+		{
+			if (status_ == SCANNER_ERR_OK
+				|| status_ == SCANNER_ERR_DEVICE_DOUBLE_FEEDING)	// 双张特殊处理，视为成功
+			{
+				SANE_Bool	has_paper = SANE_FALSE;
+				
+				get_scanner_paperon(has_paper);
+				if (has_paper == SANE_TRUE)
+					handled = false;
+				else
+					ret = SCANNER_ERR_DEVICE_NO_PAPER;
+			}
+			else
+				ret = status_;
+		}
+	}
+
+	return ret;
+}
 int hg_scanner::start(void)
 {
-	user_cancel_ = false;
+	int		ret = SCANNER_ERR_OK;
+	bool	handled = false;
 
-	return status_;
+	if (user_cancel_)
+	{
+		user_cancel_ = false;	// stopped by user, reset flag and starting a new scanning ...
+		VLOG_MINI_1(LOG_LEVEL_DEBUG_INFO, "start after user stopped just now while with %d image(s) in queue, a new scanning will to be started ...\n", final_imgs_.size());
+	}
+	else
+	{
+		ret = wait_one_image_from_start(handled);
+		if (handled)
+		{
+			VLOG_MINI_2(LOG_LEVEL_DEBUG_INFO, "start in previous scanning and result is %s, image count %d\n", hg_scanner_err_description(ret), final_imgs_.size());
+			return ret;
+		}
+	}
+
+	// clear ...
+	imgs_.Clear();
+	final_imgs_.clear();
+	usb_img_index_ = final_img_index_ = 0;
+	status_ = SCANNER_ERR_OK;
+
+	// start ...
+	ret = do_start();
+
+	if (ret == SCANNER_ERR_OK)
+	{
+		// wait ONE picture or stopped
+		ret = wait_one_image_from_start(handled);
+	}
+	VLOG_MINI_1(LOG_LEVEL_DEBUG_INFO, "start scanning result = %s\n", hg_scanner_err_description(ret));
+
+	return ret;
 }
 int hg_scanner::get_image_info(SANE_Parameters* ii, int len)
 {
@@ -4197,9 +4298,21 @@ int hg_scanner::read_image_data(unsigned char* buf, int* len)
 }
 int hg_scanner::stop(void)
 {
-	user_cancel_ = true;
+	int ret = SCANNER_ERR_OK;
 
-	return status_;
+	user_cancel_ = true;
+	ret = do_stop();
+
+	// wait until really stopped ...
+	if (ret == SCANNER_ERR_OK)
+	{
+		while (is_running() != THREAD_RUNNING_IDLE)
+			std::this_thread::sleep_for(std::chrono::milliseconds(3));
+		ret = status_;
+	}
+	VLOG_MINI_1(LOG_LEVEL_DEBUG_INFO, "user stopped result = %s\n", hg_scanner_err_description(ret));
+
+	return ret;
 }
 int hg_scanner::reset(void)
 {
diff --git a/hgdriver/hgdev/hg_scanner.h b/hgdriver/hgdev/hg_scanner.h
index 98bcc4b..f2fe824 100644
--- a/hgdriver/hgdev/hg_scanner.h
+++ b/hgdriver/hgdev/hg_scanner.h
@@ -439,6 +439,7 @@ protected:
     int save_final_image(hg_imgproc::LPIMGHEAD head, void* buf, uint32_t id = -1);
 
     void adjust_filling_hole(LPSCANCONF conf);
+    int wait_one_image_from_start(bool& handled);
 
     ////////////////////////////////////////////////////////////////
     // 新增自定义伽玛曲线及扫描区域属性 - 2022-05-05
@@ -461,6 +462,9 @@ protected:
     bool    is_white_0_;                    // 是否‘0’代表白色
 
 public:
+    int start(void);
+    int stop(void);
+
     void set_ui_callback(sane_callback cb, bool enable_async_io);
     void set_dev_family(const char* family);
     void set_read_over_with_no_data(bool no_data);
@@ -487,10 +491,10 @@ public:
     int is_running(void);   // return thread_running
 
 public:
-    virtual int start(void);
+    virtual int do_start(void) = 0;
+    virtual int do_stop(void) = 0;
     virtual int get_image_info(SANE_Parameters* ii, int len);
     virtual int read_image_data(unsigned char* buf, int* len);
-    virtual int stop(void);
     virtual int reset(void);
     virtual int device_io_control(unsigned long code, void* data, unsigned* len);
     virtual int discard_all_images(void) = 0;
diff --git a/hgdriver/hgdev/hg_scanner_200.cpp b/hgdriver/hgdev/hg_scanner_200.cpp
index 558a08f..e3c08ef 100644
--- a/hgdriver/hgdev/hg_scanner_200.cpp
+++ b/hgdriver/hgdev/hg_scanner_200.cpp
@@ -265,7 +265,7 @@ void hg_scanner_200::thread_handle_usb_read(void)
 	}
 	VLOG_MINI_2(LOG_LEVEL_DEBUG_INFO, "USB thread exit with code: %s, status = %s\n", hg_scanner_err_name(ret), hg_scanner_err_description(status_));
 }
-int hg_scanner_200::start(void)
+int hg_scanner_200::do_start(void)
 {
 	bool	handled = false;
 	int		ret = try_third_app_handle_start(handled),
@@ -318,7 +318,7 @@ int hg_scanner_200::start(void)
 
 	return ret;
 }
-int hg_scanner_200::stop(void)
+int hg_scanner_200::do_stop(void)
 {
 	int ret = SCANNER_ERR_OK;
 
@@ -337,7 +337,8 @@ int hg_scanner_200::stop(void)
 	{
 		status_ = SCANNER_ERR_DEVICE_STOPPED;
 	}
-	return status_;
+
+	return ret;
 }
 int hg_scanner_200::writeusb(USBCB &usb)
 {
diff --git a/hgdriver/hgdev/hg_scanner_200.h b/hgdriver/hgdev/hg_scanner_200.h
index 5779b02..4785dfa 100644
--- a/hgdriver/hgdev/hg_scanner_200.h
+++ b/hgdriver/hgdev/hg_scanner_200.h
@@ -50,8 +50,8 @@ public:
 	~hg_scanner_200();
 
 public:
-	virtual int start(void)override;	
-	virtual int stop(void)override;	
+	virtual int do_start(void) override;
+	virtual int do_stop(void) override;
 
 private:
  	int initdevice();
diff --git a/hgdriver/hgdev/hg_scanner_239.cpp b/hgdriver/hgdev/hg_scanner_239.cpp
index 9e2c1bf..80ec946 100644
--- a/hgdriver/hgdev/hg_scanner_239.cpp
+++ b/hgdriver/hgdev/hg_scanner_239.cpp
@@ -1337,6 +1337,7 @@ void hg_scanner_239::thread_get_dves_image(void)
 		{
 			std::lock_guard<std::mutex>      lock(io_lock_);
 
+			memset(buf, 0, size);
 			ret = io_->read_interrupt(buf, &size);
 			io_->set_timeout(1000);
 		}
@@ -1354,7 +1355,7 @@ void hg_scanner_239::thread_get_dves_image(void)
 
 			if (is_auto_paper_scan && sw.elapsed_s() >= is_auto_paper_scan_exit_time && is_auto_paper_scan_exit_time != 0)
 			{
-				stop();
+				do_stop();
 				notify_ui_working_status(from_default_language(STATU_DESC_SCANNER_ERR_DEVICE_EXIT_WAIT_SCAN), SANE_EVENT_ERROR, status_);
 				VLOG_MINI_1(LOG_LEVEL_DEBUG_INFO, "auto paper scan exit :%s\n", from_default_language(STATU_DESC_SCANNER_ERR_DEVICE_EXIT_WAIT_SCAN));
 			}
@@ -1397,7 +1398,7 @@ void hg_scanner_239::thread_get_dves_image(void)
 				&& status_ != SCANNER_ERR_DEVICE_AUTO_FAIL_INFO
 				)
 			{
-				if (info->From != setting3399::IMG && status_ != SCANNER_ERR_DEVICE_DOUBLE_FEEDING)
+				if (info->From != setting3399::IMG /*&& status_ != SCANNER_ERR_DEVICE_DOUBLE_FEEDING*/)
 					svdevs_err_.push_back(status_);
 			}
 
@@ -1413,13 +1414,13 @@ void hg_scanner_239::thread_get_dves_image(void)
 				while (get_image_count() > 0)
 				{
 
-					ret = read_one_image_from_usb((status_ == SCANNER_ERR_DEVICE_DOUBLE_FEEDING && dev_conf_.params_3399.double_out_en) ? IMG_STATUS_DOUBLE : IMG_STATUS_OK);
+					ret = read_one_image_from_usb((status_ == SCANNER_ERR_DEVICE_DOUBLE_FEEDING /*&& dev_conf_.params_3399.double_out_en*/) ? IMG_STATUS_DOUBLE : IMG_STATUS_OK);
 					//if (status_ == SCANNER_ERR_DEVICE_DOUBLE_FEEDING)
 					//	svdevs_err_.push_back(IMG_STATUS_DOUBLE);
 					count++;
-					if (ret != SCANNER_ERR_OK
-						&& ret != SCANNER_ERR_CREATE_FILE_FAILED
-						&& ret != SCANNER_ERR_WRITE_FILE_FAILED)
+					//if (ret != SCANNER_ERR_OK
+					//	&& ret != SCANNER_ERR_CREATE_FILE_FAILED
+					//	&& ret != SCANNER_ERR_WRITE_FILE_FAILED)
 						break;
 				}
 			}
@@ -1441,15 +1442,22 @@ void hg_scanner_239::thread_get_dves_image(void)
 			else
 				std::this_thread::sleep_for(std::chrono::milliseconds(2000));
 
+			int rest = 0;
 			while (get_image_count() > 0)
 			{
 				ret = read_one_image_from_usb();
-				count++;
+				rest++;
 				if (ret != SCANNER_ERR_OK
 					&& ret != SCANNER_ERR_CREATE_FILE_FAILED
 					&& ret != SCANNER_ERR_WRITE_FILE_FAILED)
 					break;
 			}
+			count += rest;
+			if (rest)
+			{
+				VLOG_MINI_1(LOG_LEVEL_DEBUG_INFO, "STOPSCAN message is ahead of %d image(s)!\n", rest);
+			}
+
 			if (user_cancel_ && !is_auto_paper_scan)
 			{
 				if (status_ && status_ != SCANNER_ERR_DEVICE_STOPPED)		// thread_handle_image_process maybe call stop() when insufficient memory occurs .
@@ -1492,7 +1500,7 @@ void hg_scanner_239::thread_get_dves_image(void)
 		else if (info->From == setting3399::V4L2)
 		{
 			VLOG_MINI_2(LOG_LEVEL_WARNING, "V4L2 message received, code = %d, index = %d\n", info->Code, info->Img_Index);
-			//	stop();
+			//	do_stop();
 			break;
 		}
 		else if (info->From == setting3399::AutoCorrect)
@@ -1526,7 +1534,7 @@ void hg_scanner_239::thread_handle_usb_read(void)
 		thread_get_dves_image();
 }
 
-int hg_scanner_239::start(void)
+int hg_scanner_239::do_start(void)
 {
 	bool	handled = false;
 	int		ret = try_third_app_handle_start(handled),
@@ -1536,8 +1544,6 @@ int hg_scanner_239::start(void)
 		return ret;
 
 
-	user_cancel_ = false;
-
 	split3399_ = 0;
 
 	cb_mem_ = true;
@@ -1614,15 +1620,14 @@ int hg_scanner_239::start(void)
 
 	return ret;
 }
-int hg_scanner_239::stop(void)
+int hg_scanner_239::do_stop(void)
 {
 	int ret = SCANNER_ERR_OK; 
 
-	user_cancel_ = true;
-
 	ret = write_command(setting3399::SC_STOP);
 	io_->set_timeout(500);
-	return status_;
+
+	return ret;
 }
 int hg_scanner_239::reset(void)
 {
@@ -1824,9 +1829,9 @@ int hg_scanner_239::get_scanner_paperon(SANE_Bool& type)
 	int ret = read_register(setting3399::SR_GET_PAPERON, &val); //0无纸 1有纸
 	if (ret == SCANNER_ERR_OK)
 	{
-		type = val == 0 ? false : true;
+		type = val == 0 ? SANE_FALSE : SANE_TRUE;
 	}
-	VLOG_MINI_1(LOG_LEVEL_WARNING, "get_scanner_paperon is(%s)\n", !type ? hg_scanner_err_description(SCANNER_ERR_DEVICE_NO_PAPER) : hg_scanner_err_description(SCANNER_ERR_OK));
+	VLOG_MINI_1(LOG_LEVEL_WARNING, "get_scanner_paperon is(%s)\n", val == 0 ? hg_scanner_err_description(SCANNER_ERR_DEVICE_NO_PAPER) : "paper on");
 
 	return ret;
 }
diff --git a/hgdriver/hgdev/hg_scanner_239.h b/hgdriver/hgdev/hg_scanner_239.h
index e35a103..940abea 100644
--- a/hgdriver/hgdev/hg_scanner_239.h
+++ b/hgdriver/hgdev/hg_scanner_239.h
@@ -86,8 +86,8 @@ public:
 public:
 	//virtual int get_image_info(IMG_PARAM* ii) override;
 	//virtual int read_image_data(unsigned char* buf, int* len) override;
-	virtual int start(void) override;
-	virtual int stop(void) override;
+	virtual int do_start(void) override;
+	virtual int do_stop(void) override;
 	virtual int reset(void) override;
 	virtual int device_io_control(unsigned long code, void* data, unsigned* len) override;
 	virtual int get_roller_life(void) override;
diff --git a/hgdriver/hgdev/hg_scanner_300.cpp b/hgdriver/hgdev/hg_scanner_300.cpp
index d420326..188d119 100644
--- a/hgdriver/hgdev/hg_scanner_300.cpp
+++ b/hgdriver/hgdev/hg_scanner_300.cpp
@@ -334,7 +334,7 @@ int hg_scanner_300::get_roller_life(void)
 {
 	return pid_ == 300 ? 150000 : 200000;
 }
-int hg_scanner_300::start(void)
+int hg_scanner_300::do_start(void)
 {
 	bool	handled = false;
 	int		ret = try_third_app_handle_start(handled), //sane调用是每次都会调用一次start和stop
@@ -408,7 +408,7 @@ int hg_scanner_300::start(void)
 	VLOG_MINI_1(LOG_LEVEL_WARNING, "----------Main start scan status : %s----------\n", hg_scanner_err_description(ret));
 	return ret;
 }
-int hg_scanner_300::stop(void)
+int hg_scanner_300::do_stop(void)
 {
 	int ret = SCANNER_ERR_OK;
 
@@ -431,7 +431,7 @@ int hg_scanner_300::stop(void)
 	}
 	//final_imgs_.clear();
 
-	return status_;
+	return ret;
 }
 int hg_scanner_300::writeusb(USBCB &usb)
 {
@@ -554,7 +554,7 @@ int hg_scanner_300::get_img_data(std::shared_ptr<tiny_buffer>& imagedata)
 	else
 	{
 		VLOG_MINI_1(LOG_LEVEL_DEBUG_INFO, "Read image data from USB err: %s\n", hg_scanner_err_name(ret));
-		stop();
+		do_stop();
 		string str = STATU_DESC_SCANNER_ERR_DEVICE_GET_IMAGE_ERR;
 		str = str + '-' + STATU_DESC_SCANNER_ERR_DEVICE_STOPPED;
 		notify_ui_working_status(str.c_str(), SANE_EVENT_ERROR, ret);
diff --git a/hgdriver/hgdev/hg_scanner_300.h b/hgdriver/hgdev/hg_scanner_300.h
index d3aa3ec..e971dbe 100644
--- a/hgdriver/hgdev/hg_scanner_300.h
+++ b/hgdriver/hgdev/hg_scanner_300.h
@@ -51,8 +51,9 @@ public:
 	hg_scanner_300(const char* dev_name,int pid, usb_io* io);
 	~hg_scanner_300();
 public:
-	virtual int start(void)override;	
-	virtual int stop(void)override;	
+	virtual int do_start(void) override;
+	virtual int do_stop(void) override;
+
 private:
 	int set_kernelsnap_ver();
 	int agreement(TwSS tw,int align);
diff --git a/hgdriver/hgdev/hg_scanner_302.cpp b/hgdriver/hgdev/hg_scanner_302.cpp
index 9a9cbc5..df67ac0 100644
--- a/hgdriver/hgdev/hg_scanner_302.cpp
+++ b/hgdriver/hgdev/hg_scanner_302.cpp
@@ -1020,7 +1020,7 @@ void hg_scanner_302::thread_handle_usb_read(void)
 				VLOG_MINI_1(LOG_LEVEL_FATAL, "V4L2 error: %d\n", info->Code);
 				{
 					bool cancel = user_cancel_;
-					stop();
+					do_stop();
 					user_cancel_ = cancel;
 					go = false;
 				}
@@ -1052,7 +1052,7 @@ void hg_scanner_302::thread_handle_usb_read(void)
 	}
 	VLOG_MINI_2(LOG_LEVEL_DEBUG_INFO, "USB thread exit with code: %s, status = %s\n", hg_scanner_err_name(ret), hg_scanner_err_name(status_));
 }
-int hg_scanner_302::start(void)
+int hg_scanner_302::do_start(void)
 {
 	
 	bool	handled = false;
@@ -1129,7 +1129,7 @@ int hg_scanner_302::start(void)
 
 	return ret;
 }
-int hg_scanner_302::stop(void)
+int hg_scanner_302::do_stop(void)
 {
 	std::lock_guard<std::mutex>      lock(io_lock_);
 	int ret = SCANNER_ERR_OK;
@@ -1139,7 +1139,7 @@ int hg_scanner_302::stop(void)
 //	io_->set_timeout(500);
 	//final_imgs_.clear();
 
-	return status_;
+	return ret;
 }
 int hg_scanner_302::reset(void)
 {
diff --git a/hgdriver/hgdev/hg_scanner_302.h b/hgdriver/hgdev/hg_scanner_302.h
index 9cd5af8..37864fb 100644
--- a/hgdriver/hgdev/hg_scanner_302.h
+++ b/hgdriver/hgdev/hg_scanner_302.h
@@ -83,10 +83,9 @@ public:
 	~hg_scanner_302();
 
 public:
-	virtual int start(void) override;
-	//virtual int get_image_info(IMG_PARAM* ii) override;
-	//virtual int read_image_data(unsigned char* buf, int* len) override;
-	virtual int stop(void) override;
+	virtual int do_start(void) override;
+	virtual int do_stop(void) override;
+
 	virtual int reset(void) override;
 	virtual int device_io_control(unsigned long code, void* data, unsigned* len) override;
 
diff --git a/hgdriver/hgdev/hg_scanner_306.cpp b/hgdriver/hgdev/hg_scanner_306.cpp
index 8eb1a5b..e733ba0 100644
--- a/hgdriver/hgdev/hg_scanner_306.cpp
+++ b/hgdriver/hgdev/hg_scanner_306.cpp
@@ -294,7 +294,7 @@ int hg_scanner_306::get_roller_life(void)
 {
 	return pid_ == 300 ? 150000 : 200000;
 }
-int hg_scanner_306::start(void)
+int hg_scanner_306::do_start(void)
 {
 	bool	handled = false;
 	int		ret = try_third_app_handle_start(handled), //sane调用是每次都会调用一次start和stop
@@ -368,7 +368,7 @@ int hg_scanner_306::start(void)
 	VLOG_MINI_1(LOG_LEVEL_WARNING, "----------Main start scan status : %s----------\n", hg_scanner_err_description(ret));
 	return ret;
 }
-int hg_scanner_306::stop(void)
+int hg_scanner_306::do_stop(void)
 {
 	int ret = SCANNER_ERR_OK;
 
@@ -391,7 +391,7 @@ int hg_scanner_306::stop(void)
 	}
 	//final_imgs_.clear();
 
-	return status_;
+	return ret;
 }
 int hg_scanner_306::writeusb(USBCB &usb)
 {
diff --git a/hgdriver/hgdev/hg_scanner_306.h b/hgdriver/hgdev/hg_scanner_306.h
index 6f290f2..47c91bf 100644
--- a/hgdriver/hgdev/hg_scanner_306.h
+++ b/hgdriver/hgdev/hg_scanner_306.h
@@ -52,8 +52,9 @@ public:
 	hg_scanner_306(const char* dev_name,int pid, usb_io* io);
 	~hg_scanner_306();
 public:
-	virtual int start(void)override;	
-	virtual int stop(void)override;	
+	virtual int do_start(void) override;
+	virtual int do_stop(void) override;
+
 private:
 	int set_kernelsnap_ver();
 	int agreement(TwSS tw,int align);