为什么当我尝试在laravel中下载PDF文件时，打开一个包含奇怪字符的文件？

我有以下代码可以在laravel中下载PDF

控制器

public function doDownload($id){

        $servicio = Servicio::find($id);
        $array = explode('/', $servicio->RutaPDF);
        $path = '/home/web-apps/marsur/public/servicio/'.$array[1].'/ordedeservicio.pdf'; //array[1] contain a number

        header("Content-Type: application/octet-stream");

        header("Content-Disposition: attachment; filename=" . urlencode($path));   
        header("Content-Type: application/octet-stream");
        header("Content-Type: application/download");
        header("Content-Description: File Transfer");            
        header("Content-Length: " . filesize($path));
        flush(); // this doesn't really matter.
        $fp = fopen($path, "r");
        while (!feof($fp))
        {
            echo fread($fp, 65536);
            flush(); // this is essential for large downloads
        } 
        fclose($fp); 
}

路线

Route::get('servicio/download/{id}', array('uses' => 'ServicioController@doDownload'));

当我Postman用来测试时，会出现

我该如何解决？