读字“ěščřž..“通过php函数从Word文档文件中返回菱形问号

我在PHP中找到了函数，它可以很好地读取MS Word.doc文件，但是当文件包含一些"ěščř..."时。字符，它返回 diamont 字符中的问号（无法识别的字符？

函数看起来像这样

if ( file_exists($filename) ) {
        if ( ($fh = fopen($filename, 'r')) !== false ) {
            $headers = fread($fh, 0xA00);
            # 1 = (ord(n)*1) ; Document has from 0 to 255 characters
            $n1 = ( ord($headers[0x21C]) - 1 );
            # 1 = ((ord(n)-8)*256) ; Document has from 256 to 63743 characters
            $n2 = ( ( ord($headers[0x21D]) - 8 ) * 256 );
            # 1 = ((ord(n)*256)*256) ; Document has from 63744 to 16775423 characters
            $n3 = ( ( ord($headers[0x21E]) * 256 ) * 256 );
            # (((ord(n)*256)*256)*256) ; Document has from 16775424 to 4294965504 characters
            $n4 = ( ( ( ord($headers[0x21F]) * 256 ) * 256 ) * 256 );
            # Total length of text in the document
            $textLength = ($n1 + $n2 + $n3 + $n4);
            $extracted_plaintext = fread($fh, $textLength);
            # if you want the plain text with no formatting, do this
            //echo $extracted_plaintext;
            echo mb_detect_encoding($extracted_plaintext);
            # if you want to see your paragraphs in a web page, do this
            echo nl2br($extracted_plaintext);
        }
    }

我也试图将字符编码更改为 UTF-8，其中我有这样的整个网络内容

$extracted_plaintext = iconv("UTF-8","UTF-8//IGNORE",$extracted_plaintext);

但它只会删除无效字符，因此文本也是不可读的。所以我不确定，这个问题是否真的在字符集中，或者其他什么？我认为 UTF-8 是正确的，因为如果我使用 echo mb_detect_encoding($extracted_plaintext);返回 UTF-8

编辑：这是附件示例