Excluding iPad from wp_is_mobile

I am eperiencing a very annoying problem. I built my website with media queries and is_mobile (thinking is_mobile would be the same as smaller screens. How foolish of me.) but after some testing apparently the iPad kind of screws it up (okay, actually I did).

All my problems could easily be solved if I could exclude an iPad from the wp_is_mobile function. How do I rewrite that function?

function wp_is_mobile() {
    static $is_mobile;

    if ( isset($is_mobile) )
        return $is_mobile;

    if ( empty($_SERVER['HTTP_USER_AGENT']) ) {
        $is_mobile = false;
    } elseif ( strpos($_SERVER['HTTP_USER_AGENT'], 'Mobile') !== false // many mobile devices (all iPhone, iPad, etc.)
        || strpos($_SERVER['HTTP_USER_AGENT'], 'Android') !== false
        || strpos($_SERVER['HTTP_USER_AGENT'], 'Silk/') !== false
        || strpos($_SERVER['HTTP_USER_AGENT'], 'Kindle') !== false
        || strpos($_SERVER['HTTP_USER_AGENT'], 'BlackBerry') !== false
        || strpos($_SERVER['HTTP_USER_AGENT'], 'Opera Mini') !== false ) {
            $is_mobile = true;
    } else {
        $is_mobile = false;
    }

    return $is_mobile;
}

How would I change this?

t f’s answer got me thinking. Actually, I can use the core function and adapt it as I like but just put everything in a new function. So here goes:

function my_wp_is_mobile() {
    static $is_mobile;

    if ( isset($is_mobile) )
        return $is_mobile;

    if ( empty($_SERVER['HTTP_USER_AGENT']) ) {
        $is_mobile = false;
    } elseif (
        strpos($_SERVER['HTTP_USER_AGENT'], 'Android') !== false
        || strpos($_SERVER['HTTP_USER_AGENT'], 'Silk/') !== false
        || strpos($_SERVER['HTTP_USER_AGENT'], 'Kindle') !== false
        || strpos($_SERVER['HTTP_USER_AGENT'], 'BlackBerry') !== false
        || strpos($_SERVER['HTTP_USER_AGENT'], 'Opera Mini') !== false ) {
            $is_mobile = true;
    } elseif (strpos($_SERVER['HTTP_USER_AGENT'], 'Mobile') !== false && strpos($_SERVER['HTTP_USER_AGENT'], 'iPad') == false) {
            $is_mobile = true;
    } elseif (strpos($_SERVER['HTTP_USER_AGENT'], 'iPad') !== false) {
        $is_mobile = false;
    } else {
        $is_mobile = false;
    }

    return $is_mobile;
}