使用Ajax PHP不会将文件移动到其他位置

我尝试使用Ajax和PHP单击按钮后上传文件并将其移动到文件夹。确实会成功返回true，但是上载的文件不会移动到目标文件夹。这是Ajax上传的片段

btnsubmit   = $(".submit");

//the function for handling button click
     btnsubmit.click(function(){
            var file_data = $('#uploaded_img').prop('files')[0];   
            var form_data = new FormData();                  
            form_data.append('file', file_data);

            $.ajax({
                url: 'upload_img_custom.php',
                cache: false,
                contentType: false,
                processData: false,
                data: form_data,                         
                type: 'POST',
                success: function(php_script_response){
                    alert(php_script_response);
                }
            });
        });

这是PHP文件

<?php
    $upload_directory = "../uploads/Customized/";
    if (isset($_FILES['uploaded_img']))
    {
        $uploadedFileName=$_FILES['uploaded_img']['name'];
        $targetPath=time().$uploadedFileName; //time is concatenated to make filenames unique
        if($uploadedFileName != '')
        {
            $targetPath=time().$uploadedFileName;
            move_uploaded_file($uploadedFileName, $upload_directory."".$targetPath);
        }
    }
    header('Location: customize.php?upload=success');
?>

HTML（仅重要部分）

<form method=POST id=customize-form action ="" enctype=multipart/form-data>
     <div id=step3 class='options step'>
        <section class=section-title>Image</section>
        <div class=image-display><img id=image-disp src="" width=99 style="text-align:center" /></div> //div for displaying uploaded image
        <section style="margin-bottom:10px">
            <label class="paragraph-font2 full-width">Choose what you want on the top of your cake:</label>
        </section>
        <section style="margin-bottom:15px">
            <input class="paragraph-font2 full-width" type=file name=uploaded_img id=uploaded_img accept="image/*">
        </section>
    </div>
    <button type=submit class='btn btn-info action submit'><span class='glyphicon glyphicon-shopping-cart'></span> Add to cart</button>
</form>

我已经检查了上传限制。我要上传的文件只有170KB。我设置的上限为20M。“自定义”文件夹位于xampp htdocs中此项目的另一个文件夹内。